workflow validation failed if base branch's name has # in it

[seunghyeoks]

Describe the bug
If change base branch into something like feat/#689-v1.2.0, then Claude Code actions failed with workflow validation failed error. If we rename base brach(of course, no changes in workflows) like develop/v1.2.0, then workflows works fine.

To Reproduce
Steps to reproduce the behavior:

1. Go to your repository (where Claude Code actions workflow already exists) in Github
2. Go to Settings
3. In General, find Default branch menu
4. change Default branch into something has # in it

Expected behavior
A clear and concise description of what you expected to happen.

Then Claude Code actions start to fail with below message

Warning: Skipping action due to workflow validation: Workflow validation failed. The workflow file must exist and have identical content to the version on the repository's default branch. If you're seeing this on a PR when you first add a code review workflow file to your repository, this is normal and you should ignore this error.

Screenshots
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Workflow yml file
If it's not sensitive, consider including a paste of your full Claude workflow.yml file.

API Provider

[ ] Anthropic First-Party API (default)
[ ] AWS Bedrock
[ ] GCP Vertex
I used Github apps for claude connection

Additional context
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[seunghyeoks]

My guess is that the # character prevents it from identifying what the base branch is in the first place.

In that case, I think either the warning message should be updated, or support for the # character should be added.