fix CI

[andrewlyu-boop]

Support defensive best practice for CI workflow

Motivation and Context

I found a little bug in CI workflow which supports shell commands, this fix uses environment variables to ensure that GitHub actions expressions are never directly interpolated into shell commands.

How Has This Been Tested?

Yes, I tested it through my forked project and the misbehavior is resolved, there is no command executed anymore even when I set the branch name to connect$(env).

Breaking Changes

Will users need to update their code or configurations?
Not necessary.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context

Thanks for the support from Anthropic staff on hackerone.