Update towncrier requirement from >=24.8.0 to >=25.8.0 (#228)

Updates the requirements on [towncrier](https://github.com/twisted/towncrier) to permit the latest version.
- [Release notes](https://github.com/twisted/towncrier/releases)
- [Changelog](https://github.com/twisted/towncrier/blob/trunk/NEWS.rst)
- [Commits](twisted/towncrier@24.8.0...25.8.0)

---
updated-dependencies:
- dependency-name: towncrier
  dependency-version: 25.8.0
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

pyproject.toml

@@ -67,7 +67,7 @@ tests = [
     "pytest-cov>=6.1.1",
 ]
 changelog = [
-    "towncrier>=24.8.0",
+    "towncrier>=25.8.0",
 ]
 docs = [
     "pydata-sphinx-theme>=0.16.1",