chore(deps): bump types-pyyaml in /requirements/lintrunner

Bumps [types-pyyaml](https://github.com/python/typeshed) from 6.0.12.20250915 to 6.0.12.20260508.
- [Commits](https://github.com/python/typeshed/commits)

---
updated-dependencies:
- dependency-name: types-pyyaml
  dependency-version: 6.0.12.20260408
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

requirements/lintrunner/requirements.txt

@@ -4,6 +4,6 @@ lintrunner-adapters>=0.8.0
 ruff==0.15.1
 # MYPY
 mypy==2.0.0
-types-PyYAML==6.0.12.20250915
+types-PyYAML==6.0.12.20260508
 # EDITORCONFIG-CHECKER
 editorconfig-checker==3.4.1