chore(deps): update dependency black to v26 (#236)

This PR contains the following updates:

| Package | Change | [Age](https://docs.renovatebot.com/merge-confidence/) | [Confidence](https://docs.renovatebot.com/merge-confidence/) |
|---|---|---|---|
| [black](https://github.com/psf/black) ([changelog](https://github.com/psf/black/blob/main/CHANGES.md)) | `<25.12.1,>=25.12.0` → `<26.1.1,>=26.1.0` | ![age](https://developer.mend.io/api/mc/badges/age/pypi/black/26.1.0?slim=true) | ![confidence](https://developer.mend.io/api/mc/badges/confidence/pypi/black/25.12.0/26.1.0?slim=true) |

---

### Release Notes

<details>
<summary>psf/black (black)</summary>

### [`v26.1.0`](https://github.com/psf/black/blob/HEAD/CHANGES.md#2610)

[Compare Source](psf/black@25.12.0...26.1.0)

##### Highlights

Introduces the 2026 stable style ([#&#8203;4892](psf/black#4892)), stabilizing the following changes:

- `always_one_newline_after_import`: Always force one blank line after import
  statements, except when the line after the import is a comment or an import statement
  ([#&#8203;4489](psf/black#4489))
- `fix_fmt_skip_in_one_liners`: Fix `# fmt: skip` behavior on one-liner declarations,
  such as `def foo(): return "mock" # fmt: skip`, where previously the declaration would
  have been incorrectly collapsed ([#&#8203;4800](psf/black#4800))
- `fix_module_docstring_detection`: Fix module docstrings being treated as normal
  strings if preceded by comments ([#&#8203;4764](psf/black#4764))
- `fix_type_expansion_split`: Fix type expansions split in generic functions ([#&#8203;4777](psf/black#4777))
- `multiline_string_handling`: Make expressions involving multiline strings more compact
  ([#&#8203;1879](psf/black#1879))
- `normalize_cr_newlines`: Add `\r` style newlines to the potential newlines to
  normalize file newlines both from and to ([#&#8203;4710](psf/black#4710))
- `remove_parens_around_except_types`: Remove parentheses around multiple exception
  types in `except` and `except*` without `as` ([#&#8203;4720](psf/black#4720))
- `remove_parens_from_assignment_lhs`: Remove unnecessary parentheses from the left-hand
  side of assignments while preserving magic trailing commas and intentional multiline
  formatting ([#&#8203;4865](psf/black#4865))
- `standardize_type_comments`: Format type comments which have zero or more spaces
  between `#` and `type:` or between `type:` and value to `# type: (value)` ([#&#8203;4645](psf/black#4645))

The following change was not in any previous stable release:

- Regenerated the `_width_table.py` and added tests for the Khmer language ([#&#8203;4253](psf/black#4253))

This release alo bumps `pathspec` to v1 and fixes inconsistencies with Git's
`.gitignore` logic ([#&#8203;4958](psf/black#4958)). Now, files will be ignored if a pattern matches them, even
if the parent directory is directly unignored. For example, Black would previously
format `exclude/not_this/foo.py` with this `.gitignore`:

```
exclude/
!exclude/not_this/
```

Now, `exclude/not_this/foo.py` will remain ignored. To ensure `exclude/not_this/` and
all of it's children are included in formatting (and in Git), use this `.gitignore`:

```
*/exclude/*
!*/exclude/not_this/
```

This new behavior matches Git. The leading `*/` are only necessary if you wish to ignore
matching subdirectories (like the previous behavior did), and not just matching root
directories.

##### Output

- Explicitly shutdown the multiprocessing manager when run in diff mode too ([#&#8203;4952](psf/black#4952))

##### Integrations

- Upgraded PyPI upload workflow to use Trusted Publishing ([#&#8203;4611](psf/black#4611))

</details>

---

### Configuration

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♻ **Rebasing**: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update again.

---

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---

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Reviewed-on: https://git.tainton.uk/luke/instant-msg-api/pulls/236
Co-authored-by: renovate[bot] <[email protected]>
Co-committed-by: renovate[bot] <[email protected]>

Author: renovate[bot]

pyproject.toml

@@ -26,7 +26,7 @@ build-backend = "pdm.backend"
 
 [tool.uv]
 dev-dependencies = [
-    "black<25.12.1,>=25.12.0",
+    "black<26.1.1,>=26.1.0",
     "coverage<8.0.0,>=7.6.10",
     "pylint<4.1.0,>=4.0.0",
     "pylint-exit<2.0.0,>=1.2.0",