Fix #32954 (#32955)

`/bin/s6-svscan` is actuall located at `/usr/bin/s6-svscan`

Author: stuzer05

Diff for: Dockerfile

@@ -78,7 +78,7 @@ ENV GITEA_CUSTOM=/data/gitea
 VOLUME ["/data"]
 
 ENTRYPOINT ["/usr/bin/entrypoint"]
-CMD ["/bin/s6-svscan", "/etc/s6"]
+CMD ["/usr/bin/s6-svscan", "/etc/s6"]
 
 COPY --from=build-env /tmp/local /
 COPY --from=build-env /go/src/code.gitea.io/gitea/gitea /app/gitea/gitea