drone: fix cron job for upstream syncing

.drone.yml

@@ -4,25 +4,6 @@ type: docker
 name: Upstreaming
 
 steps:
-  - name: "Setup git repos and SSH access"
-    image: alpine/git
-    when:
-      event:
-        - cron
-      cron:
-        - sync-main-with-upstream
-        - sync-b12f-with-main
-        - sync-teutat3s-with-main
-    environment:
-      GITEA_SSH_KEY:
-        from_secret: gitea_ssh_key
-    commands:
-      - ./.drone/setup_ssh.sh
-      - git fetch
-      - git remote add devos git@git.b12f.io:pub-solar/devos
-      - git remote set-url origin git@git.b12f.io:pub-solar/os
-      - git fetch --all
-
   - name: "Sync 'devos' branch with upstream"
     image: alpine/git
     when:
@@ -35,7 +16,10 @@ steps:
         from_secret: gitea_ssh_key
     commands:
       - ./.drone/setup_ssh.sh
-      - git checkout origin/devos
+      - git remote add devos git@git.b12f.io:pub-solar/devos
+      - git remote set-url origin git@git.b12f.io:pub-solar/os
+      - git fetch --all
+      - git checkout -b devos --track origin/devos
       - git merge -X theirs devos/main
       - git push origin devos