Use bundler-cache to speed up CI

See puppetlabs/puppet@86820ee

This intentionally doesn't use bundler-cache for the mend workflow, since we
want the latest versions of all of our dependencies that still satisfy our
constraints.

This doesn't update the acceptance_tests workflow because it does a bundle
install for both the top-level Gemfile and the one in the acceptance dir.

.github/workflows/checks.yaml

@@ -21,6 +21,6 @@ jobs:
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: '2.7'
-      - run: bundle install --jobs 3 --retry 3
+          bundler-cache: true
       - run: bundle exec rubocop --parallel
 

.github/workflows/coverage.yaml

@@ -24,7 +24,7 @@ jobs:
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: '2.7'
-      - run: bundle install --jobs 3 --retry 3
+          bundler-cache: true
       - run: bundle exec rake spec
 
       - name: Publish code coverage

.github/workflows/integration_tests.yaml

@@ -24,6 +24,8 @@ jobs:
           - {os: windows-2019, ruby: '2.7'}
           - {os: windows-2019, ruby: '3.2'} # with openssl 3
     runs-on: ${{ matrix.cfg.os }}
+    env:
+      BUNDLE_SET: 'with integration'
     steps:
       - name: Checkout current PR
         uses: actions/checkout@v4
@@ -32,7 +34,5 @@ jobs:
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.cfg.ruby }}
-      - run: gem update bundler
-      - run: bundle config set --local with integration
-      - run: bundle install --jobs 3 --retry 3
+          bundler-cache: true
       - run: bundle exec rake spec_integration

.github/workflows/unit_tests.yaml

@@ -33,8 +33,7 @@ jobs:
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
-      - run: gem update bundler
-      - run: bundle install --jobs 3 --retry 3
+          bundler-cache: true
       - run: bundle exec rake spec_random
 
   windows_unit_tests:
@@ -53,6 +52,5 @@ jobs:
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
-      - run: gem update bundler
-      - run: bundle install --jobs 3 --retry 3
+          bundler-cache: true
       - run: bundle exec rake spec_random