Scheduled builds: start from main as it is now

Run 18 (schedule) checked out e06d965f, where its schedule was registered,
because the pushes after it said [skip ci]; its merge of upstream was then
behind main and the push was rejected.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

.forgejo/workflows/build-arm64.yml

@@ -41,6 +41,14 @@ jobs:
         with:
           fetch-depth: 0
 
+      - name: Build main as it is now
+        # A scheduled run checks out the commit its schedule was registered
+        # at, which can be behind main (see build.yml).
+        if: github.event_name == 'schedule'
+        run: |
+          git fetch --no-tags origin main
+          git checkout -B main FETCH_HEAD
+
       - name: Point downloads at our mirrors
         # As build.yml.
         run: |

.forgejo/workflows/build.yml

@@ -59,6 +59,11 @@ jobs:
         run: |
           git config user.name "forgejo-actions"
           git config user.email "actions@forge.quinefoundation.com"
+          # A scheduled run checks out the commit its schedule was registered
+          # at, the last push without [skip ci], which can be behind main:
+          # merge onto main as it is now, or the push below is rejected.
+          git fetch --no-tags origin main
+          git checkout -B main FETCH_HEAD
           # Our pull mirror of github.com/ublue-os/aurora, synced hourly.
           git fetch --no-tags "$MIRRORS/mirror-ublue-os-aurora.git" main
           before=$(git rev-parse HEAD)