chore(deps): keep the black and isort versions of CI and hooks in step (#172)

Merging this moves the black and isort pre-commit hooks to 26.10.0 and
9.0.2, the versions CI installs since #170 and #171, and makes Renovate
update black and isort in `requirements-dev.txt` and
`.pre-commit-config.yaml` in one pull request (the `>=` floors in
`pyproject.toml` get no update from Renovate and stay as they are). The
hooks and the CI formatter check then use the same versions again.

## Summary

- #169 pinned black and isort in `requirements-dev.txt` to the hook
versions. Renovate then bumped only `requirements-dev.txt` (#170, #171):
its pre-commit manager is disabled by default, so the hook revs never
move.
- `renovate.json` enables the pre-commit manager (the organisation
preset `netresearch/renovate-config` does the same) and groups every
black and isort dependency (`black`, `psf/black`, `isort`,
`PyCQA/isort`) under one group.
- `.pre-commit-config.yaml`: black rev 26.5.1 → 26.10.0, isort rev 8.0.1
→ 9.0.2. The tree is already formatted for both: `pre-commit run black
--all-files` and `pre-commit run isort --all-files` pass without
changing a file.

## Linked issues / PRs

Follows #169, #170 and #171.

## Type of change

- [x] Chore / CI / deps (`chore:`)

## Test plan

- [x] `bunx --package renovate renovate-config-validator renovate.json`
(valid)
- [x] `pre-commit run black --all-files` and `pre-commit run isort
--all-files` with the new revs (pass, no file changed)

## Checklist

- [x] Conventional Commits (`type(scope): description`)
- [x] Commits signed (`git commit -S --signoff`)
- [x] `CHANGELOG.md` updated for user-visible changes (none)
- [x] Relevant `AGENTS.md` files updated if structure / commands changed
(none)
- [x] No secrets, credentials, or PII committed

_Assisted by claude-code:claude-opus-5-5 —
[Session](https://claude.ai/code/session_018YeAfZRDbYWzRMVUPmZDXj)_

Author: CybotTM

.pre-commit-config.yaml

@@ -25,14 +25,14 @@ repos:
         files: ^(cli_audit/|tests/|audit\.py$)
 
   - repo: https://github.com/PyCQA/isort
-    rev: 8.0.1
+    rev: 9.0.2
     hooks:
       - id: isort
         files: ^(cli_audit/|tests/|audit\.py$)
         args: ['--profile=black']
 
   - repo: https://github.com/psf/black
-    rev: 26.5.1
+    rev: 26.10.0
     hooks:
       - id: black
         files: ^(cli_audit/|tests/|audit\.py$)

renovate.json

@@ -2,5 +2,18 @@
   "$schema": "https://docs.renovatebot.com/renovate-schema.json",
   "extends": [
     "config:recommended"
+  ],
+  "pre-commit": {
+    "enabled": true
+  },
+  "packageRules": [
+    {
+      "description": "black and isort run twice: as pre-commit hooks (.pre-commit-config.yaml) and in CI from requirements-dev.txt. Update every copy in one pull request so the hook and CI format alike.",
+      "matchPackageNames": [
+        "/^(psf\\/)?black$/i",
+        "/^(pycqa\\/)?isort$/i"
+      ],
+      "groupName": "black and isort"
+    }
   ]
 }