Update ffmpeg to 8.1 from 8.0.1

Author: bump

Dockerfile

@@ -3,7 +3,7 @@ FROM eclipse-temurin:25-alpine AS builder
 WORKDIR /app
 
 # bump: ffmpeg /static-ffmpeg:([\d.]+)/ docker:mwader/static-ffmpeg|/\d+\./|*
-COPY --from=mwader/static-ffmpeg:8.0.1 /ff* /usr/bin/
+COPY --from=mwader/static-ffmpeg:8.1 /ff* /usr/bin/
 
 COPY . .
 RUN --mount=type=cache,target=/root/.gradle ./gradlew check installDist --no-daemon