Ensure clearing caches by removing $RUNNER_TOOL_CACHE (#427)

Fixes #425

Author: kachick

.github/workflows/ci-ruby.yml

@@ -41,6 +41,9 @@ jobs:
       # https://github.com/kachick/irb-power_assert/blob/104834846baf5caa1e8536a11c43acdd56fc849c/CONTRIBUTING.md#adding-dependencies-for-this-gem
       BUNDLE_WITHOUT: development
     steps:
+      - name: Ensure clearing GitHub provided tool cache. See GH-425 for detail
+        run: |
+          rm -rf "$RUNNER_TOOL_CACHE"
       - uses: actions/checkout@v6
       - uses: ruby/setup-ruby@90be1154f987f4dc0fe0dd0feedac9e473aa4ba8 # v1.286.0
         with: