Remove redundant Rubocop checks

.github/workflows/__rubocop-multi-language.yml

@@ -25,18 +25,8 @@ jobs:
     strategy:
       matrix:
         include:
-        - os: ubuntu-20.04
-          version: stable-20210308
-        - os: ubuntu-20.04
-          version: stable-20210319
-        - os: ubuntu-20.04
-          version: stable-20210809
         - os: ubuntu-latest
           version: cached
-        - os: ubuntu-latest
-          version: latest
-        - os: ubuntu-latest
-          version: nightly-latest
     name: RuboCop multi-language
     timeout-minutes: 45
     runs-on: ${{ matrix.os }}

pr-checks/checks/rubocop-multi-language.yml

@@ -1,6 +1,8 @@
 name: "RuboCop multi-language"
 description: "Tests using RuboCop to analyze a multi-language repository and then using the CodeQL Action to upload the resulting SARIF"
 operatingSystems: ["ubuntu"]
+# This check doesn't use CodeQL, so the `version` matrix variable is unused.
+versions: ["cached"]
 steps:
   - name: Set up Ruby
     uses: ruby/setup-ruby@v1