[ci] Update branch management for batch release

[chunhtai]

based on go/batch-release-branch option 2

Needs to add flutter github bot to be able to bypass branch protection first

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[chunhtai]

since it is going to be used by both jobs, i move it out

[chunhtai]

since now the workflow creates differernt release branches, this check is obsolete

[gemini-code-assist]

Code Review

This pull request renames the branch-for-batch-release command to branches-for-batch-release and updates the release branch naming convention to include the package version. It introduces logic to create and push these versioned branches and updates the publish and repo-package-info-check commands accordingly. Review feedback indicates that the startsWith branch matching logic may be too broad for packages with overlapping names and suggests using git branch -f to handle existing local branches more robustly.

[gemini-code-assist]

The startsWith check is potentially too broad. If a package name is a prefix of another (e.g., pkg and pkg-foo), a release branch for pkg-foo (e.g., release-pkg-foo-1.0.0) would match the startsWith('release-pkg-') check for the pkg package.

While the tool currently limits processing to a single package per run, using an exact match including the version would be more robust and prevent accidental multi-package publishing if the tool's constraints change in the future.