Bump pillow from 11.3.0 to 12.1.1 in /tools/wptrunner (#57712)

* Bump pillow from 11.3.0 to 12.1.1 in /tools/wptrunner

Bumps [pillow](https://github.com/python-pillow/Pillow) from 11.3.0 to 12.1.1.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/main/CHANGES.rst)
- [Commits](python-pillow/Pillow@11.3.0...12.1.1)

---
updated-dependencies:
- dependency-name: pillow
  dependency-version: 12.1.1
  dependency-type: direct:production
...

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

* Update requirements.txt

---------

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: jgraham <james@hoppipolla.co.uk>

Author: dependabot[bot]

tools/wptrunner/requirements.txt

@@ -5,8 +5,8 @@ mozlog==8.0.0
 mozprocess==1.4.0
 mozshellutil==1.0.0
 packaging==25.0
-pillow==10.4.0; python_version < '3.9'
-pillow==11.3.0; python_version >= '3.9'
+pillow==11.3.0; python_version == '3.9'
+pillow==12.1.1; python_version >= '3.10'
 requests==2.32.3
 types-requests==2.32.0.20241016
 urllib3==2.2.2