chore(deps): update dependency ruby to v2.7.8 (#210)

Ref: PACT-445

Co-authored-by: pactflow-renovate-bot[bot] <186667433+pactflow-renovate-bot[bot]@users.noreply.github.com>

Author: pactflow-renovate-bot[bot]

.github/workflows/test_pact_cli_tools_cross_os.yml

@@ -79,7 +79,7 @@ jobs:
         uses: ruby/setup-ruby@v1 
         if: ${{ (env.PACT_TOOL == 'ruby_cli' || env.PACT_TOOL == 'ruby_standalone') && runner.os == 'Linux' }}
         with:
-          ruby-version: 2.7
+          ruby-version: 2.7.8
           bundler: none
       # we add a fallback for windows/darwin runners as they cannot run docker
       - name: 🔧 install-pact-ruby-cli (also runs for macOS/docker)