test: add option to startup script to not load the newest plugin.

Test/test.sh

@@ -4,14 +4,16 @@ JELLYFIN=jellyfin/jellyfin
 
 set -eu
 cd "$(dirname "$0")"
-pwd
+mkdir -p ./cache ./media ./config/plugins/jellyfin-smart-playlist
+if [ "$#" -eq  1 ] && [ "$1" = '--skip-build' ]; then
+    :
+else
     (
         cd ../Jellyfin.Plugin.SmartPlaylist/
         dotnet build
     )
-pwd
-mkdir -p ./cache ./media ./config/plugins/jellyfin-smart-playlist
     cp ../Jellyfin.Plugin.SmartPlaylist/bin/Debug/net8.0/jellyfin-smart-playlist.dll ./config/plugins/jellyfin-smart-playlist/
+fi
 docker pull "$JELLYFIN"
 docker run --rm --user "$(id -u):$(id -g)" \
     -v ./cache:/cache \