Add some libraries and a call to fc-cache to the Dockerfile (#8899)

these libraries were loaded until recently, include them just
in case they are used (jpeg will most probably be used by
weasyprint)

Dockerfile

@@ -36,7 +36,9 @@ RUN poetry export -f requirements.txt --without-hashes --only main | poetry run
 FROM base
 
 # these libs are necessary for operation
-RUN apk --no-cache add libmagic cairo pango ttf-opensans
+RUN apk --no-cache add libmagic cairo pango ttf-opensans && \
+ apk --no-cache add postgresql-libs libxslt jpeg zlib libxml2 # those *might* be useful
+RUN fc-cache -f
 
 COPY --from=builder /opt/pysetup/.venv /opt/pysetup/.venv