Bump pillow from 12.1.0 to 12.1.1 in /frontend

Bumps [pillow](https://github.com/python-pillow/Pillow) from 12.1.0 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@12.1.0...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]

frontend/requirements.txt

@@ -4,7 +4,7 @@ furo==2025.12.19
 graphviz==0.21
 ipython==9.9.0
 pdf2image==1.17.0
-pillow==12.1.0
+pillow==12.1.1
 pydot-ng==2.0.0
 Pygments==2.19.2
 pyparsing==3.3.2

frontend/requirements_frozen.txt

@@ -24,7 +24,7 @@ packaging==26.0
 parso==0.8.5
 pdf2image==1.17.0
 pexpect==4.9.0
-pillow==12.1.0
+pillow==12.1.1
 prompt_toolkit==3.0.52
 ptyprocess==0.7.0
 pure_eval==0.2.3