Bump pillow from 10.3.0 to 12.1.1 in /build/sphinx

Bumps [pillow](https://github.com/python-pillow/Pillow) from 10.3.0 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@10.3.0...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>

Author: dependabot[bot]

build/sphinx/requirements.txt

@@ -45,7 +45,7 @@ myst-parser==4.0.1
     # via -r requirements.in
 packaging==25.0
     # via sphinx
-pillow==10.3.0
+pillow==12.1.1
     # via -r requirements.in
 pydantic==2.11.4
     # via
@@ -60,8 +60,6 @@ pygments==2.17.2
 pyyaml==6.0.1
     # via myst-parser
 requests==2.32.2
-    # version 2.32.2 replaces 2.32.0 as it has been yanked from PyPI,
-    # due to the conflict with a CVE mitigation
     # via
     #   sphinx
     #   sphinx-immaterial