Merge pull request #29361 from overleaf/msm-hotfix-5-5-6

[CE/SP] Hotfix 5.5.6

GitOrigin-RevId: f5390576b4ea0c9d7e5a2c145130b3f01a8bc431

server-ce/hotfix/5.5.6/Dockerfile

@@ -0,0 +1,5 @@
+FROM sharelatex/sharelatex:5.5.5
+
+RUN apt update \
+    && unattended-upgrade --verbose --no-minimal-upgrade-steps \
+    && rm -rf /var/lib/apt/lists/*