fix: pipelines ties cli version with cdk-assets version (#31261)

cdk-assets is no longer being versioned in line with the cli or with aws-cdk-lib. Because every change must be backward compatible, we can just use `latest` for cdk-assets (not that we will soon be releasing a new major version of cdk-assets but we are releasing that with the `v3-latest` tag at present. When we are ready to swap versions, we will begin labeling the v3 line as `latest` and make the v2 line `v2-latest` as it will be in maintenance mode.

Note: the linter and potentially the build will fail for this initially because an integ test needs to be updated.

Closes #31253.


### Checklist
- [ ] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/@aws-cdk-testing/framework-integ/test/pipelines/test/integ.newpipeline-with-file-system-locations.js.snapshot/PipelinesFileSystemLocations.template.json

@@ -1778,7 +1778,7 @@
      ]
     },
     "Source": {
-     "BuildSpec": "{\n  \"version\": \"0.2\",\n  \"phases\": {\n    \"install\": {\n      \"commands\": [\n        \"npm install -g cdk-assets@2\"\n      ]\n    },\n    \"build\": {\n      \"commands\": [\n        \"cdk-assets --path \\\"assembly-PipelinesFileSystemLocations-Beta/PipelinesFileSystemLocationsBetaStack18199ECAE.assets.json\\\" --verbose publish \\\"8289faf53c7da377bb2b90615999171adef5e1d8f6b88810e5fef75e6ca09ba5:current_account-current_region\\\"\"\n      ]\n    }\n  }\n}",
+     "BuildSpec": "{\n  \"version\": \"0.2\",\n  \"phases\": {\n    \"install\": {\n      \"commands\": [\n        \"npm install -g cdk-assets@latest\"\n      ]\n    },\n    \"build\": {\n      \"commands\": [\n        \"cdk-assets --path \\\"assembly-PipelinesFileSystemLocations-Beta/PipelinesFileSystemLocationsBetaStack18199ECAE.assets.json\\\" --verbose publish \\\"8289faf53c7da377bb2b90615999171adef5e1d8f6b88810e5fef75e6ca09ba5:current_account-current_region\\\"\"\n      ]\n    }\n  }\n}",
      "Type": "CODEPIPELINE"
     },
     "VpcConfig": {

packages/@aws-cdk-testing/framework-integ/test/pipelines/test/integ.newpipeline-with-vpc.js.snapshot/PipelineStack.template.json

@@ -1973,7 +1973,7 @@
      ]
     },
     "Source": {
-     "BuildSpec": "{\n  \"version\": \"0.2\",\n  \"phases\": {\n    \"install\": {\n      \"commands\": [\n        \"npm install -g cdk-assets@2\"\n      ]\n    },\n    \"build\": {\n      \"commands\": [\n        \"cdk-assets --path \\\"assembly-PipelineStack-Beta/PipelineStackBetaStack1E6541489.assets.json\\\" --verbose publish \\\"8289faf53c7da377bb2b90615999171adef5e1d8f6b88810e5fef75e6ca09ba5:current_account-current_region\\\"\"\n      ]\n    }\n  }\n}",
+     "BuildSpec": "{\n  \"version\": \"0.2\",\n  \"phases\": {\n    \"install\": {\n      \"commands\": [\n        \"npm install -g cdk-assets@latest\"\n      ]\n    },\n    \"build\": {\n      \"commands\": [\n        \"cdk-assets --path \\\"assembly-PipelineStack-Beta/PipelineStackBetaStack1E6541489.assets.json\\\" --verbose publish \\\"8289faf53c7da377bb2b90615999171adef5e1d8f6b88810e5fef75e6ca09ba5:current_account-current_region\\\"\"\n      ]\n    }\n  }\n}",
      "Type": "CODEPIPELINE"
     },
     "VpcConfig": {
@@ -2072,7 +2072,7 @@
      ]
     },
     "Source": {
-     "BuildSpec": "{\n  \"version\": \"0.2\",\n  \"phases\": {\n    \"install\": {\n      \"commands\": [\n        \"npm install -g cdk-assets@2\"\n      ]\n    },\n    \"build\": {\n      \"commands\": [\n        \"cdk-assets --path \\\"assembly-PipelineStack-Beta/PipelineStackBetaStack1E6541489.assets.json\\\" --verbose publish \\\"ac76997971c3f6ddf37120660003f1ced72b4fc58c498dfd99c78fa77e721e0e:current_account-current_region\\\"\"\n      ]\n    }\n  }\n}",
+     "BuildSpec": "{\n  \"version\": \"0.2\",\n  \"phases\": {\n    \"install\": {\n      \"commands\": [\n        \"npm install -g cdk-assets@latest\"\n      ]\n    },\n    \"build\": {\n      \"commands\": [\n        \"cdk-assets --path \\\"assembly-PipelineStack-Beta/PipelineStackBetaStack1E6541489.assets.json\\\" --verbose publish \\\"ac76997971c3f6ddf37120660003f1ced72b4fc58c498dfd99c78fa77e721e0e:current_account-current_region\\\"\"\n      ]\n    }\n  }\n}",
      "Type": "CODEPIPELINE"
     },
     "VpcConfig": {

packages/aws-cdk-lib/pipelines/lib/codepipeline/codepipeline.ts

@@ -817,8 +817,6 @@ export class CodePipeline extends PipelineBase {
   }
 
   private publishAssetsAction(node: AGraphNode, assets: StackAsset[]): ICodePipelineActionFactory {
-    const installSuffix = this.cliVersion ? `@${this.cliVersion}` : '';
-
     const commands = assets.map(asset => {
       const relativeAssetManifestPath = path.relative(this.myCxAsmRoot, asset.assetManifestPath);
       return `cdk-assets --path "${toPosixPath(relativeAssetManifestPath)}" --verbose publish "${asset.assetSelector}"`;
@@ -840,7 +838,7 @@ export class CodePipeline extends PipelineBase {
     const script = new CodeBuildStep(node.id, {
       commands,
       installCommands: [
-        `npm install -g cdk-assets${installSuffix}`,
+        'npm install -g cdk-assets@latest',
       ],
       input: this._cloudAssemblyFileSet,
       buildEnvironment: {

packages/aws-cdk-lib/pipelines/lib/private/cli-version.ts

@@ -38,4 +38,4 @@ export function findUp(name: string, directory: string): string | undefined {
   }
 
   return findUp(name, path.dirname(absoluteDirectory));
-}
+}

packages/aws-cdk-lib/pipelines/test/compliance/assets.test.ts

@@ -253,7 +253,7 @@ describe('basic pipeline', () => {
         BuildSpec: Match.serializedJson(Match.objectLike({
           phases: {
             install: {
-              commands: ['npm install -g cdk-assets@1.2.3'],
+              commands: ['npm install -g aws-cdk@1.2.3'],
             },
           },
         })),
@@ -388,7 +388,7 @@ test('can supply pre-install scripts to asset upload', () => {
       BuildSpec: Match.serializedJson(Match.objectLike({
         phases: {
           install: {
-            commands: ['npm config set registry https://registry.com', 'npm install -g cdk-assets@2'],
+            commands: ['npm config set registry https://registry.com', 'npm install -g cdk-assets@latest'],
           },
         },
       })),