Fix docker tmp dir permission issue

Author: freyacodes

Dockerfile

@@ -1,5 +1,5 @@
 FROM azul/zulu-openjdk:25-jre-latest
-RUN groupadd -r -g 999 ukulele && useradd -rd /opt/ukulele -g ukulele -u 999 -ms /bin/bash ukulele && mkdir -p /opt/ukulele/tmp
+RUN groupadd -r -g 999 ukulele && useradd -rd /opt/ukulele -g ukulele -u 999 -ms /bin/bash ukulele && mkdir -p /opt/ukulele/tmp && chown ukulele:ukulele /opt/ukulele/tmp
 COPY --chown=ukulele:ukulele build/libs/ukulele.jar /opt/ukulele/ukulele.jar
 USER ukulele
 WORKDIR /opt/ukulele/