Don't install supervisord, use a separate container instead

Dockerfile

@@ -2,18 +2,13 @@ FROM docker.io/library/nextcloud:24.0.8
 
 RUN apt-get update && \
     apt-get install -y \
-    supervisor \
     ffmpeg \
     libmagickcore-6.q16-6-extra \
 	smbclient &&\
 	apt clean &&\
-    rm -rf /var/lib/apt/lists/* &&\
-    mkdir /var/log/supervisord /var/run/supervisord
+    rm -rf /var/lib/apt/lists/*
 
-COPY $GITHUB_WORKSPACE/supervisord.conf /
 COPY $GITHUB_WORKSPACE/enable-previews /usr/local/bin
 COPY $GITHUB_WORKSPACE/previews.conf /
 
 ENV NEXTCLOUD_UPDATE=1
-
-CMD ["/usr/bin/supervisord", "-c", "/supervisord.conf"]