python: bump pytest from 9.0.3 to 9.1.1 in /python/railjson_generator

Bumps [pytest](https://github.com/pytest-dev/pytest) from 9.0.3 to 9.1.1.
- [Release notes](https://github.com/pytest-dev/pytest/releases)
- [Changelog](https://github.com/pytest-dev/pytest/blob/main/CHANGELOG.rst)
- [Commits](pytest-dev/pytest@9.0.3...9.1.1)

---
updated-dependencies:
- dependency-name: pytest
  dependency-version: 9.1.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

python/railjson_generator/pyproject.toml

@@ -11,7 +11,7 @@ dependencies = ["osrd-schemas", "osrd-schemas-auto"]
 check = [
   "pyright~=1.1.410",
   "pytest-cov~=7.1.0",
-  "pytest~=9.0.3",
+  "pytest~=9.1.1",
   "ruff~=0.15.17",
 ]