Update webmentions data, package-lock, requirements, and character images

- Modified webmentions JSON data to reorder entries and update URLs.
- Updated `electron-to-chromium` version in `package-lock.json` from 1.5.155 to 1.5.157.
- Added `pillow==11.2.1` to `requirements.txt`.
- Updated multiple character image files in the `static/Characters` directory.

.pre-commit-config.yaml

@@ -29,7 +29,7 @@ repos:
       - id: python-no-log-warn
       - id: python-use-type-annotations
   - repo: https://github.com/asottile/pyupgrade
-    rev: v3.19.1
+    rev: v3.20.0
     hooks:
       - id: pyupgrade
         args: [--py312-plus]