workflow: use rebase instead of merge

.gitea/workflows/update-flake.yaml

@@ -22,7 +22,7 @@ jobs:
           git config user.name "Gitea Actions"
           git config user.email "actions@gitea.local"
 
-      - name: Merge master branch
+      - name: Rebase from master branch
         shell: bash
         run: |
             commits_ahead=$(git rev-list --count HEAD..origin/master)
@@ -30,14 +30,14 @@ jobs:
             git log --oneline -5
             echo "----------"
             git log --oneline -5 origin/master
+            echo .
 
             if [ $commits_ahead -ne 0 ]
             then
-              git fetch origin
-              git merge -X theirs --squash origin/master
-              git commit -m "Merge master branch squashed $(date -I)"
+              git rebase -X theirs origin/master
+              git push --force-with-lease origin flake-updates
             else
-              echo "Merge not necessary"
+              echo "Rebase not necessary"
             fi
 
       - name: Set up Nix
@@ -54,4 +54,4 @@ jobs:
           git diff --cached --quiet && echo "No changes to commit." && exit 0
 
           git commit -m "Update flake.lock $(date -I)"
-          git push origin flake-updates
+          git push --force-with-lease origin flake-updates