docs: replace Black references with ruff-format

[Shikhar-395]

Follow up to #12778.

Updates stale Python style guidance so docs refer to Ruff for linting and ruff format for formatting instead of Black. Also removes the unused [tool.black] config from pyproject.toml.

Note: root requirements_test.txt already has no Black dependency. The remaining black entry is in vendor/infogami/requirements_test.txt, which belongs to the Infogami submodule and needs an Infogami side PR/submodule bump.

Stakeholders

@RayBB

[mekarpeles]

Thank you for the contribution, @Shikhar-395!

🤖 Copilot has been assigned for an initial review.

The linked issue (#12778) hasn't been triaged yet — triage happens on Mondays and Fridays. There are currently 73 open non-draft PRs ahead of yours.

PR triage checklist (maintainers / Pam)

• PR description — not empty; explains what the change does and how to verify it
• References an issue — PR body contains a #NNN reference
  • Linked issue is triaged — has a Priority: * label (not just Needs: Triage)
  • Linked issue is assigned — has at least one assignee
• Commit history clean — no WIP/fixup/conflict noise; commit messages are meaningful
• CI passing — no failing check-runs
• Test cases present — if the change touches substantive logic, test coverage exists or is explained
• Proof of testing — PR body includes a description of what was tested, a screenshot, or a video

Note

This comment was automatically generated by Pam, Open Library's Project AI Manager, on behalf of @mekarpeles. Pam is designed to provide status visibility, perform basic project management functions and relevant codebase research, and provide actionable feedback so contributors aren't left waiting.

[Copilot]

Pull request overview

Updates repository documentation/configuration to reflect the post-Black migration, aligning Python style guidance with Ruff-based linting/formatting and removing leftover Black configuration from pyproject.toml.

Changes:

• Remove the unused [tool.black] configuration (and related comments) from pyproject.toml.
• Update AI/dev guidance docs to reference Ruff for linting and Ruff’s formatter instead of Black.
• Refresh the “bridge” instruction files (AGENTS.md, .github/copilot-instructions.md) to match the canonical docs/ai/README.md.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
pyproject.toml	Removes obsolete Black configuration now that formatting is handled via Ruff tooling.
docs/ai/README.md	Updates canonical AI/dev documentation to replace Black references with Ruff-based formatting guidance.
AGENTS.md	Updates quick-reference guidance to match the Ruff formatter transition.
.github/copilot-instructions.md	Updates Copilot quick-reference guidance to match the Ruff formatter transition.

Comments suppressed due to low confidence (1)

AGENTS.md:41

• Consider naming the formatter as ruff format / “Ruff formatter” rather than “ruff-format” (which is the pre-commit hook id) so developers don’t mistake it for a standalone command.

- **Python:** Ruff for linting and ruff-format for formatting, line length 162, double quotes

[Shikhar-395]

@RayBB, PTAL

[RayBB]

Great cleanup thanks!