build: drop md5 and sha256 files from releases

GitHub now shows a sha256 digest for every uploaded release asset, so
the sidecar hash files only clutter the asset list.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

.github/workflows/release.yml

@@ -60,7 +60,7 @@ jobs:
           make -j1 release || (cat $dir/test/test-suite.log; false)
           ls -lF ../
           mkdir -p artifacts/
-          mv ../*.tar.* artifacts/
+          mv ../*.tar.gz artifacts/
       - name: Upload Test Results
         if: always()
         uses: actions/upload-artifact@v7