fix: allow empty string comparison - #384

In .github/workflows/ci.yml (Line: 26, Col: 11): Error from called workflow puppetlabs/cat-github-actions/.github/workflows/gem_ci.yml@main (Line: 54, Col: 13): Conditional expression contains literal text outside replacement tokens. This will cause the expression to always evaluate to truthy. Did you mean to put the entire expression inside ${{ }}?