Bump pillow from 10.3.0 to 10.4.0 in /tools

Bumps [pillow](https://github.com/python-pillow/Pillow) from 10.3.0 to 10.4.0.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/main/CHANGES.rst)
- [Commits](python-pillow/Pillow@10.3.0...10.4.0)

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

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

tools/wptrunner/requirements.txt

@@ -4,7 +4,7 @@ mozinfo==1.2.3  # https://bugzilla.mozilla.org/show_bug.cgi?id=1621226
 mozlog==8.0.0
 mozprocess==1.3.1
 packaging==24.0
-pillow==10.3.0
+pillow==10.4.0
 requests==2.32.3
 six==1.16.0
 urllib3==2.2.2