CI bump to GHC 9.8 and latest majors; use build plan as cache key

.github/workflows/ci.yml

@@ -1,49 +1,59 @@
 name: CI
 on:
-  - push
-  - pull_request
-jobs:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
 
+jobs:
   cabal:
     name: ${{ matrix.os }} - GHC ${{ matrix.ghc }}
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
         os: [ubuntu-latest, macOS-latest, windows-latest]
         ghc:
-          - 9.2.7
-          - 9.4.4
-          - 9.6.1
+          - 9.8
+          - 9.6
+          - 9.4
+          - 9.2
       fail-fast: false
 
     steps:
-    - uses: actions/checkout@v2
+    - uses: actions/checkout@v4
 
-    - uses: haskell/actions/setup@v2
-      id: setup-haskell-cabal
-      name: Setup Haskell
+    - name: Setup Haskell
+      uses: haskell-actions/setup@v2
+      id:   setup
       with:
         ghc-version: ${{ matrix.ghc }}
 
+    - name: Configure
+      run: |
+        cabal configure --enable-tests --enable-benchmarks --test-show-details=direct
+        cabal build all --dry-run
+
     - name: Restore cache
       uses: actions/cache/restore@v3
+      id:   cache
       with:
-        key: ${{ runner.os }}-${{ matrix.ghc }}-${{ github.sha }}
-        path: ${{ steps.setup-haskell-cabal.outputs.cabal-store }}
-        restore-keys: ${{ runner.os }}-${{ matrix.ghc }}-
+        path: ${{ steps.setup.outputs.cabal-store }}
+        key:  ${{ runner.os }}-ghc-${{ steps.setup.outputs.ghc-version }}-plan-${{ hashfiles('dist-newstyle/cache/plan.json') }}
+        restore-keys: |
+              ${{ runner.os }}-ghc-${{ steps.setup.outputs.ghc-version }}-
 
-    - name: Build
-      run: |
-        cabal configure --enable-tests --enable-benchmarks --test-show-details=direct
-        cabal build all
+    - name: Build dependencies
+      run: cabal build all --dependencies-only
 
-    - name: Test
-      run: |
-        cabal test all
+    - run: cabal build all
+    - run: cabal test all
+    - run: cabal haddock
+    - run: cabal check
+    - run: cabal sdist
 
     - name: Save cache
       uses: actions/cache/save@v3
-      if: always()
+      if:   always()
       with:
-        key: ${{ runner.os }}-${{ matrix.ghc }}-${{ github.sha }}
-        path: ${{ steps.setup-haskell-cabal.outputs.cabal-store }}
+        key:  ${{ steps.cache.outputs.cache-primary-key }}
+        path: ${{ steps.setup.outputs.cabal-store }}