Bump pillow from 11.1.0 to 11.3.0 in /tools

Bumps [pillow](https://github.com/python-pillow/Pillow) from 11.1.0 to 11.3.0.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/main/CHANGES.rst)
- [Commits](python-pillow/Pillow@11.1.0...11.3.0)

---
updated-dependencies:
- dependency-name: pillow
  dependency-version: 11.3.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

tools/wptrunner/requirements.txt

@@ -5,7 +5,7 @@ mozlog==8.0.0
 mozprocess==1.3.1
 packaging==25.0
 pillow==10.4.0; python_version < '3.9'
-pillow==11.1.0; python_version >= '3.9'
+pillow==11.3.0; python_version >= '3.9'
 requests==2.32.3
 types-requests==2.32.0.20241016
 six==1.16.0