Add missing system dependency

Author: slarse

.github/workflows/update-generated-docs.yml

@@ -17,6 +17,10 @@ jobs:
         with:
           ref: main
 
+      - run: |
+         sudo apt-get update
+         sudo apt-get install -y libdbus-1-dev
+
       - run: git clone --depth=1 https://github.com/gitbutlerapp/gitbutler ../gitbutler
       - run: ./scripts/update-manpages.sh