Update pyproject-fmt requirement from <2.3 to <2.6

Updates the requirements on [pyproject-fmt](https://github.com/tox-dev/toml-fmt) to permit the latest version.
- [Release notes](https://github.com/tox-dev/toml-fmt/releases)
- [Commits](tox-dev/toml-fmt@tox-toml-fmt/1.0.0...pyproject-fmt/2.5.0)

---
updated-dependencies:
- dependency-name: pyproject-fmt
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

pyproject.toml

@@ -91,7 +91,7 @@ develop = [
   "black<25",
   "mypy<1.14",
   "poethepoet<0.30",
-  "pyproject-fmt<2.3",
+  "pyproject-fmt<2.6",
   "ruff<0.8",
   "types-docutils==0.20.0.3",
   "validate-pyproject<0.21",