Try to correct the python version rule again

Author: mandli

.github/workflows/testing.yml

@@ -23,7 +23,7 @@ jobs:
       fail-fast: false # Probably want to turn this off for a large matrix
       matrix:
         os: [ubuntu-latest] #, macos-latest]
-        python-version: ["3.12"]
+        python-version: 3.12
         build: [optimized]
         toolchain:
           - {compiler: gcc, version: 14}