[CLD-6501] Enhance visibility for PR builds artefacts (#25141)

Co-authored-by: Akis Maziotis <akis.maziotis@mattermost.com>

server/build/Dockerfile

@@ -39,7 +39,7 @@ HEALTHCHECK --interval=30s --timeout=10s \
   CMD curl -f http://localhost:8065/api/v4/system/ping || exit 1
 
 # Configure entrypoint and command
-COPY entrypoint.sh /
+COPY --chown=mattermost:mattermost --chmod=765 entrypoint.sh /
 ENTRYPOINT ["/entrypoint.sh"]
 WORKDIR /mattermost
 CMD ["mattermost"]