Don't upgrade pip.

Author: stefanseefeld

.github/workflows/deploy-documentation.yml

@@ -17,7 +17,7 @@ jobs:
           python3-sphinx \
           xsltproc \
           docbook-xsl
-        sudo python3 -m pip install --upgrade pip
+        #sudo python3 -m pip install --upgrade pip
         sudo python3 -m pip install faber
     - name: build
       run: |