Create a program to handle release chores

[rickeylev]

There's a few tedious and mechanical steps for our release process around replacing
strings and updating docs. See RELEASING.md for all the steps.

It should be relatively easy to create a program that does the various string processing. The basic logic it needs to do is:

• Update CHANGELOG.md
  • Replace the "Unreleased" title with [X.Y.Z] - YYYY-MM-DD
  • Replace 0.0.0 with X.Y.Z
  • Replace v0-0-0 with vX-Y-Z
  • Caveat: don't modify the "unreleased template" that is commented out.
• Replace VERSION_NEXT_* markers
  • caveat: don't replace them in CONTRIBUTING.md, RELEASING.md, and .* dirs (.githhub etc)

Something more advanced could look at which VERSION_NEXT_{FEATURE,PATCH} markers exist to figure out the next semantic version, but that's just a nice to have.

Just being able to do tools/private/release.py 1.4.0 would be a big improvement over all the ad-hoc stuff we have to do today.

[XueSongTap]

Can I work on this ?

[rickeylev]

Yep, go for it!

[XueSongTap]

Proposed Script Design for Automating Release Preparation

To streamline the release steps described in [RELEASING.md](https://github.com/bazel-contrib/rules_python/blob/main/RELEASING.md), I’ve designed a Python script that automates the key parts of the manual process.

Key Features

1. Updates CHANGELOG.md:

   • Replaces ## [Unreleased] with ## [X.Y.Z] - YYYY-MM-DD
   • Replaces 0.0.0 with the actual version (e.g., 0.42.0)
   • Replaces v0-0-0 with vX-Y-Z (e.g., v0-42-0)
   • Skips modifying the "unreleased template" block that is commented out

2. Replaces VERSION_NEXT_* placeholders:

   • Replaces VERSION_NEXT_MAJOR, VERSION_NEXT_MINOR, VERSION_NEXT_PATCH with the actual version
   • Skips replacement in specific files like RELEASING.md and CONTRIBUTING.md as per the guidelines

Script Behavior

• The version (e.g., 0.42.0) is passed via a CLI argument for flexibility
• The script is intended to be run manually before creating the release commit
• It's implemented in Python and performs file-safe, regex-based replacements

Example Usage

python prepare_release.py --version 0.42.0

Let me know if this approach looks good to you, or if you'd prefer this logic to be integrated into a Bazel target or GitHub Action.
I'm happy to iterate based on your feedback!