[CI] Skip nightly dev build when no changes in the last 24 hours (#2290)

The prepare job now checks for commits in the last 24 hours before
proceeding. If there are no changes, the firmware build and docs
deploy are skipped, saving CI minutes. Manual triggers always run.

Co-authored-by: Florian <1technophile@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/build_and_docs_to_dev.yml

@@ -11,15 +11,33 @@ jobs:
     if: github.repository_owner == '1technophile'
     outputs:
       short-sha: ${{ steps.short-sha.outputs.sha }}
+      has-changes: ${{ steps.check-changes.outputs.has-changes }}
     steps:
       - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Check for recent changes
+        id: check-changes
+        run: |
+          if [ "${{ github.event_name }}" = "workflow_dispatch" ]; then
+            echo "has-changes=true" >> $GITHUB_OUTPUT
+            echo "Manual trigger, skipping change check"
+          elif git log --since='24 hours ago' --oneline | grep -q .; then
+            echo "has-changes=true" >> $GITHUB_OUTPUT
+            echo "Changes found in the last 24 hours"
+          else
+            echo "has-changes=false" >> $GITHUB_OUTPUT
+            echo "No changes in the last 24 hours, skipping build"
+          fi
       - uses: benjlevesque/short-sha@v2.1
+        if: steps.check-changes.outputs.has-changes == 'true'
         id: short-sha
         with:
           length: 6
 
   handle-firmwares:
     needs: prepare
+    if: needs.prepare.outputs.has-changes == 'true'
     name: Build and deploy development firmwares artefacts
     uses: ./.github/workflows/task-build.yml
     with:
@@ -29,6 +47,7 @@ jobs:
 
   handle-documentation:
     needs: [prepare, handle-firmwares]
+    if: needs.prepare.outputs.has-changes == 'true'
     name: Build and deploy development documentation
     uses: ./.github/workflows/task-docs.yml
     with: