Fix linter for gateway image (#1396)

gateway/Dockerfile

@@ -1,5 +1,6 @@
 FROM registry.access.redhat.com/ubi9-minimal:9.4-1134
-RUN microdnf install -y python3.11-3.11.7-1.el9_4.1 python3.11-pip-22.3.1-5.el9 python3.11-devel-3.11.7-1.el9_4.1 vim-enhanced-2:8.2.2637-20.el9_1
+RUN microdnf install -y python3.11-3.11.7-1.el9_4.1 python3.11-pip-22.3.1-5.el9 python3.11-devel-3.11.7-1.el9_4.1 vim-enhanced-2:8.2.2637-20.el9_1 &&\
+    microdnf clean all
 RUN ln -s /usr/bin/python3.11 /usr/local/bin/python3 && \
     ln -s /usr/bin/python3.11 /usr/local/bin/python &&\
     ln -s /usr/bin/pip3.11 /usr/local/bin/pip3 &&\
@@ -13,9 +14,9 @@ ENV PYTHONUNBUFFERED 1
 
 USER 0
 COPY gateway/requirements.txt .
-RUN pip install -r requirements.txt --no-cache-dir
-RUN cp -r -n /usr/local/lib64/python3.11/site-packages/symengine /usr/local/lib/python3.11/site-packages
-RUN cp -r -n /usr/local/lib/python3.11/site-packages/symengine /usr/local/lib64/python3.11/site-packages
+RUN pip install -r requirements.txt --no-cache-dir &&\
+    cp -r -n /usr/local/lib64/python3.11/site-packages/symengine /usr/local/lib/python3.11/site-packages &&\
+    cp -r -n /usr/local/lib/python3.11/site-packages/symengine /usr/local/lib64/python3.11/site-packages
 COPY gateway .
 RUN chown -R 1000:100 /usr/src/app &&\
     mkdir /usr/src/app/media && chown 1000:100 /usr/src/app/media