ci: replace deploy-nightly action with a local composite action (#16419)

WebFreak001/deploy-nightly still targets Node.js 20, so every main build
logged a deprecation warning per deploy step. The action has had no
release since 2024 and its Node 24 PR is unmerged.

The local action in .github/actions/deploy-nightly uploads the new file
under a temporary name and renames it once the upload finishes, so a
failed upload keeps the existing nightly asset. It also fails on a missing
file before deleting anything, retries transient API errors, times out
stalled transfers, handles concurrent runs, and finds the release by its
nightly-builds tag. The macOS validator DMG deploy now runs only when that
DMG was built.

.github/workflows/build_all.yml

@@ -441,14 +441,10 @@ jobs:
         path: '/__w/OrcaSlicer/OrcaSlicer/OrcaSlicer-Linux-flatpak_${{ env.ver }}_${{ matrix.variant.arch }}.flatpak'
     - name: Deploy Flatpak to nightly release
       if: github.repository == 'OrcaSlicer/OrcaSlicer' && github.ref == 'refs/heads/main'
-      uses: WebFreak001/deploy-nightly@v3.2.0
+      uses: ./.github/actions/deploy-nightly
       with:
-        upload_url: https://uploads.github.com/repos/OrcaSlicer/OrcaSlicer/releases/137995723/assets{?name,label}
-        release_id: 137995723
         asset_path: /__w/OrcaSlicer/OrcaSlicer/OrcaSlicer-Linux-flatpak_${{ env.ver }}_${{ matrix.variant.arch }}.flatpak
         asset_name: OrcaSlicer-Linux-flatpak_nightly_${{ matrix.variant.arch }}.flatpak
-        asset_content_type: application/octet-stream
-        max_releases: 1 # optional, if there are more releases than this matching the asset_name, the oldest ones are going to be deleted
     # The asset is /app (the exes link it at runtime) plus the build tree
     # slimmed to what ctest needs.
     - name: Package flatpak test asset