Test with ffmpeg 8.1

Author: WyattBlue

.github/workflows/smoke.yml

@@ -37,6 +37,7 @@ jobs:
         config:
           - {os: ubuntu-24.04, python: "3.12", ffmpeg: "8.0.1", extras: true}
           - {os: ubuntu-24.04, python: "3.10", ffmpeg: "8.0.1"}
+          - {os: ubuntu-24.04, python: "3.13", ffmpeg: "8.1"}
           - {os: ubuntu-24.04, python: "pypy3.11", ffmpeg: "8.0.1"}
           - {os: macos-14, python: "3.11", ffmpeg: "8.0.1"}