CI: use "3.13" (w/o "-dev")

.github/workflows/ci.yml

@@ -66,7 +66,7 @@ jobs:
               python-version: '3.12'
               toxenv: py312-fuse3
             - os: ubuntu-24.04
-              python-version: '3.13-dev'
+              python-version: '3.13'
               toxenv: py313-fuse3
 
     env: