Add GitHub Actions linting workflow

[joewallwork]

Okay one last linting workflow! This PR uses the security-oriented Zizmor linter to identify potential issues with GitHub Actions workflows.

I heeded its warnings and fixed a syntax error that was stopping the enzyme-bazel workflow from running previously.

[github-advanced-security]

You are seeing this message because GitHub Code Scanning has recently been set up for this repository, or this pull request contains the workflow file for the Code Scanning tool.

What Enabling Code Scanning Means:

• The 'Security' tab will display more code scanning analysis results (e.g., for the default branch).
• Depending on your configuration and choice of analysis tool, future pull requests will be annotated with code scanning analysis results.
• You will be able to see the analysis results for the pull request's branch on this overview once the scans have completed and the checks have passed.

For more information about GitHub Code Scanning, check out the documentation.