Fix workspace dependency updater (#286)

To check if our dependencies are up to date or not without spamming the
commit history, we diff from HEAD to the commit the dependency points
to. Hence, we need the commit history to decide wether to go get the
latest revision of the module.

.github/workflows/auto-updates.yaml

@@ -125,6 +125,8 @@ jobs:
         uses: actions/checkout@v4
         with:
           ref: main
+          fetch-depth: 0
+          # ^ 0 means infinity in this context. This is necessary to later be able to compute diffs.
       - name: Set up git
         uses: ./.github/actions/setup-git
         with: