chore(deps): bump actions/upload-artifact from 6 to 7

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 6 to 7.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](actions/upload-artifact@v6...v7)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '7'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/nightly-build.yml

@@ -176,7 +176,7 @@
              echo "VERSION: $UPDATED_VERSION" >> $GITHUB_STEP_SUMMARY
              
         - name: Upload APK Artifact
-          uses: actions/upload-artifact@v6
+          uses: actions/upload-artifact@v7
           with:
             name: app-debug-${{ env.GIT_COMMIT }}
             path: /tmp/app-debug-normal.apk
@@ -189,7 +189,7 @@
             mv platforms/android/app/build/outputs/apk/debug/app-debug.apk /tmp/app-debug-fdroid.apk
         
         - name: Upload APK Artifact
-          uses: actions/upload-artifact@v6
+          uses: actions/upload-artifact@v7
           if: ${{ !inputs.is_PR }}
           with:
             name: app-debug-fdroid-${{ env.GIT_COMMIT }}