install: Migrate from setup.py to pyproject.toml.

[rht]

• I use Hatch instead of Setuptools because Setuptools data-files doesn't
  support recursive file includes.

Fixes: N/A

How did you test this PR?

• Running pytest tests
• Running my own script to automate uploading a file to a given topic in a channel
• Ensured that the target data files, share/zulip has the same content as when installed in current main

• Self-reviewed the changes for clarity and maintainability
  (variable names, code reuse, readability, etc.).

Communicate decisions, questions, and potential concerns.

• Explains differences from previous plans (e.g., issue description).
• Highlights technical choices and bugs encountered.
• Calls out remaining decisions and concerns.
• Automated tests verify logic where appropriate.

Individual commits are ready for review (see commit discipline).

• Each commit is a coherent idea.
• Commit message(s) explain reasoning and motivation for changes.

Completed manual review and testing of the following:

• Visual appearance of the changes.
• Responsiveness and internationalization.
• Strings and tooltips.
• End-to-end functionality of buttons, interactions and flows.
• Corner cases, error conditions, and easily imagined bugs.

[rht]

This is superseded by readme = "README.md" in the pyproject.toml version. I checked the resulting METADATA file in the package info, and it showed the entire README.md in it.

[rht]

I confirmed that the scripts all exist in the installed virtualenv bin directory.

[rht]

The version is correctly extracted as 0.9.0.

[andersk]

Did you consider uv instead of Setuptools or Hatch?

You only migrated zulip, but we publish zulip-bots and zulip-botserver in sync with zulip, so we should migrate all three packages at once, perhaps using uv workspaces (it looks like Hatch is still missing an equivalent feature: pypa/hatch#233).

[rht]

I wasn't aware of uv_build when I created this PR. According to astral-sh/uv#3957, the issue itself was closed on July 3 2025. I suppose as of today it makes more sense to use uv_build instead.

[rht]

I just tried uv_build and found that it doesn't support dynamic version field: astral-sh/uv#11718.

[zulipbot]

Heads up @rht, we just merged some commits that conflict with the changes you made in this pull request! You can review this repository's recent commits to see where the conflicts occur. Please rebase your feature branch against the upstream/main branch and resolve your pull request's merge conflicts accordingly.