Merge pull request #2778 from yahonda/backport-2767-to-release81

Backport #2767 to release81: ci: Pin Bundler to 4.0.6 in RuboCop workflow

Author: yahonda

.github/workflows/rubocop.yml

@@ -10,12 +10,20 @@ jobs:
   build:
 
     runs-on: ubuntu-latest
+    env:
+      BUNDLER_VERSION: 4.0.6
     steps:
       - uses: actions/checkout@v6
       - name: Set up Ruby 4.0
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: 4.0
+      - name: Pin Bundler to 4.0.6 (workaround for ruby/rubygems#9536)
+        run: |
+          gem install bundler -v 4.0.6
+          ruby --version
+          gem --version
+          bundle --version
       - name: Build and run RuboCop
         run: |
           BUNDLE_ONLY=rubocop bundle install --jobs 4 --retry 3