build(deps): update pillow requirement from <10.3,>=10.2 to >=10.2,<10.4

Updates the requirements on [pillow](https://github.com/python-pillow/Pillow) to permit the latest version.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/main/CHANGES.rst)
- [Commits](python-pillow/Pillow@10.2.0...10.3.0)

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

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

requirements/testing.txt

@@ -2,6 +2,6 @@
 # --------------------
 
 GitPython>=3.1,<3.2
-Pillow>=10.2,<10.3
+Pillow>=10.2,<10.4
 pytest-cov>=4,<5.1
 validators>=0.20,<0.23