Fix GitHub workflows

Author: arithy

.github/workflows/release.yml

@@ -189,7 +189,9 @@ jobs:
       - name: Sign distribution with Sigstore
         uses: sigstore/[email protected]
         with:
-          inputs: dist/
+          inputs: |
+            ./dist/softfloatpy-*.whl
+            ./dist/softfloatpy-*.tar.gz
 
       - name: Upload artifact signatures to GitHub Release
         env: