Add building of a tarball to github actions

Author: ktmf01

.github/workflows/distcheck.yml

@@ -42,6 +42,13 @@ jobs:
       - name: Check with flac test files
         run: ./src/flac/flac -t test-files/subset/*.flac test-files/uncommon/0[5-9]*.flac test-files/uncommon/10*.flac
 
+      - name: Upload build
+        uses: actions/upload-artifact@v4
+        with:
+          name: dist-tarball
+          path: |
+            ./flac-*.tar.xz
+
       - name: Upload ABI compliance reports
         uses: actions/upload-artifact@v4
         with: