CI: Pin the codeql checkout to the branch that the CLI is based on.

Author: michaelnebel

.github/workflows/ci.yml

@@ -38,8 +38,9 @@ jobs:
         if: steps.changes.outputs.src == 'true'
         env:
           GITHUB_TOKEN: ${{ github.token }}
+          CODEQL_CLI_VERSION: ${{ env.CODEQL_CLI_VERSION }}
         run: |
-          gh repo clone github/codeql # to make stubs available for tests
+          gh repo clone github/codeql -- -b codeql-cli-${CODEQL_CLI_VERSION} # to make stubs available for tests
           codeql pack download "codeql/${{ matrix.language }}-queries"
           codeql pack install "${{ matrix.language }}/lib"
           codeql pack install "${{ matrix.language }}/src"