fix(requirements): add pillow

Newer versions of sphinx require pillow to handle some image parameters,
such as scale.

Fixes: 2a6b81e (chore(pip-upgrade): upgrade all requirements to latest, 2024-11-09)
Signed-off-by: Randolph Sapp <[email protected]>

Author: StaticRocket

requirements.txt

@@ -12,6 +12,7 @@ markdown-it-py==3.0.0
 MarkupSafe==3.0.2
 mdurl==0.1.2
 packaging==24.2
+pillow==11.0.0
 pydantic==2.10.2
 pydantic_core==2.27.1
 Pygments==2.18.0