Update pyav requirement from ~=11.4.0 to ~=11.4.1

Updates the requirements on [pyav](https://github.com/WyattBlue/pyav) to permit the latest version.
- [Release notes](https://github.com/WyattBlue/pyav/releases)
- [Commits](WyattBlue/pyav@11.4.0...11.4.1)

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

Signed-off-by: dependabot[bot] <[email protected]>

requirements.txt

@@ -1,5 +1,5 @@
 apngasm_python~=1.2.1
-pyav~=11.4.0
+pyav~=11.4.1
 beautifulsoup4~=4.12.2
 rookiepy~=0.3.2
 imageio~=2.31.6