fix: change order so that all bundler dependencies are installed in the correct bundler location

Without this it risks some bundler dependencies being installed in the user-home which then get handled differently for Dockerfiles that inherit this one

Dockerfile

@@ -21,5 +21,5 @@ USER nexus
 WORKDIR /app
 COPY --chown=nexus:nexus Gemfile Gemfile.lock ./
 COPY --chown=nexus:nexus jetbrains_gems/*.gem /tmp/
-RUN gem install --user-install /tmp/*.gem && \
-    /app/bootstrap-app-bundle.sh
+RUN /app/bootstrap-app-bundle.sh && \
+    gem install --user-install /tmp/*.gem