[3006.x]Fix tech-debt for Git Pillar data with os.walk

[dmurphy18]

What does this PR do?

Need to implement os.walk for handling traversal of Git Pillar branch names with a '/' slash in the Git branch name,

What issues does this PR fix or reference?

Fixes #67722

Previous Behavior

Previous behavior was to replace a '/' in the middle of a git branch name with a '-'

New Behavior

Leaves the git branch name unmodified and uses a os.walk to ensure the '/' in a git branch name is handled without modifying the git branch name behavior

Merge requirements satisfied?

[NOTICE] Bug fixes or features added to Salt require tests.

• Docs
• Changelog - https://docs.saltproject.io/en/master/topics/development/changelog.html
• Tests written/updated

Commits signed with GPG?

Yes

Please review Salt's Contributing Guide for best practices, including the
PR Guidelines.

See GitHub's page on GPG signing for more information about signing commits with GPG.

[dwoz]

@dmurphy18 The test:full label take precedence over all other labels. It runs the test suite just like we do for branch and nightly builds. So the test:os:full label is redundant here.