Add sparse checkout for changelog in build workflow

.github/workflows/build.yml

@@ -309,6 +309,12 @@ jobs:
     needs: [build-client, build-wheels, build-pyinstaller, build-appimage]
 
     steps:
+      - name: Checkout swingmusic
+        uses: actions/checkout@v4
+        with:
+          sparse-checkout: |
+            .github/changelog.md
+
       - name: Download client artifact
         uses: actions/download-artifact@v4
         with: