ci: adds python dependabot groups

[Vincent Biret (baywet)]

Motivation & Context

Dependabot has recently opened and merged several separate Python dependency PRs for packages that belong to the same tooling families or update cadence. This follows the same noise-reduction approach as #8059 for .NET, but scopes the grouping to the existing Python pip and uv entries.

Description & Review Guide

• What are the major changes?
  Adds Python Dependabot groups to both the pip and uv update configurations for python/:
  • pytest: groups pytest* packages. Recent Dependabot activity included a pytest workspace bump, and the root dev dependencies include multiple pytest companion packages such as pytest-asyncio, pytest-cov, pytest-xdist, pytest-timeout, and pytest-retry.
  • flit: groups flit* packages. Recent Dependabot activity included separate flit and flit-core updates, so grouping keeps related Python packaging/build tooling updates together.
  • python-type-checkers: groups mypy, pyrefly, ty, and zuban. These type-checking tools had repeated close-together Dependabot bumps and are part of the same Python dev-tooling maintenance cadence.
• What is the impact of these changes?
  Dependabot should create fewer, more coherent Python dependency update PRs for related tooling families. The change only affects Dependabot grouping and does not alter dependency versions or runtime code.
• What do you want reviewers to focus on?
  Please review whether these Python groups are scoped narrowly enough to avoid combining unrelated updates while still reducing repeated PR noise for packages that tend to be maintained together.

Related Issue

No tracked issue. There is no other open PR for this branch. Related context: #8059 applies the same grouping exercise to .NET Dependabot updates.

Contribution Checklist

• The code builds clean without any errors or warnings
• All unit tests pass, and I have added new tests where possible
• The PR follows the Contribution Guidelines
• This PR is linked to an issue and there is no other open PR for this issue (see Related Issue above).
• This is not a breaking change. If it is a breaking change, add the breaking change label (or add "[BREAKING]" to the title prefix, before or after any language prefix) — a workflow keeps the label and title prefix in sync automatically.

[Copilot]

🟢 Approval recommended

The focused configuration change has no unresolved issues.

Pull request overview

Adds Python Dependabot groups to reduce related dependency-update PR noise.

Changes:

• Groups pytest* and flit* package families.
• Groups Python type-checking tools.
• Applies identical groups to both pip and uv.

File summaries

File	Description
.github/dependabot.yml	Adds Python dependency groups for both update ecosystems.

Review details

• Files reviewed: 1/1 changed files
• Comments generated: 0
• Review effort level: Balanced

---

💡 Add a code-review agent skill for context-aware, tailored reviews. Learn more in the docs.

[github-actions]

MAF Automated Review — Iteration 1

Result: No findings
Scope: full PR (1 commit(s)): 85a7b14917ca
Model: gpt-5.6-sol-fast

Overview

The PR adds narrowly scoped Dependabot groups for related Python test, packaging, and type-checking tools in both existing Python update ecosystems. The patterns match explicit workspace dependencies, preserve the existing schedule, labels, and cooldown, and generated Python dependency changes continue through the repository's test matrix. No publishable runtime, compatibility, architectural, or security defect was established.

Reviewed the supplied pull-request change set across correctness, security/reliability, architecture, and failure behavior.
No publishable findings remained after source verification for this scope.