Create build-macos-unstable

.github/workflows/build-macos-unstable

@@ -0,0 +1,30 @@
+name: build-shotcut-macos-unstable
+
+on:
+  workflow_dispatch:
+  schedule:
+    # nightly
+    - cron: '0 12 * * *'
+
+jobs:
+  build:
+    if: ${{ github.repository_owner == 'mltframework' }}
+    runs-on: ubuntu-latest
+    steps:
+      - name: Download from S3
+        run: |
+          VERSION=$(date +"UNSTABLE-%y.%-m.%-d")
+          echo VERSION=$VERSION
+          sudo apt install -yqq s3cmd
+          s3cmd --access_key=${{ secrets.AWS_ACCESS_KEY }} --secret_key=${{ secrets.AWS_SECRET_KEY }} --stop-on-error get s3://builds.us.meltytech/shotcut-build-macos-unstable.txt
+          s3cmd --access_key=${{ secrets.AWS_ACCESS_KEY }} --secret_key=${{ secrets.AWS_SECRET_KEY }} --stop-on-error get s3://builds.us.meltytech/shotcut/shotcut-macos-unsigned-$VERSION.dmg
+
+      - name: Upload artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: unsigned-dmg
+          path: |
+            *.dmg
+
+      - name: Dump log
+        run: cat shotcut-build-macos-unstable.txt