Revert "Test Numba with Python 3.11 instead of 3.12"

This reverts commit 69319ef.

Author: maresb

.github/workflows/test.yml

@@ -102,7 +102,7 @@ jobs:
             float32: 0
             part: "tests/link/numba"
           - install-numba: 1
-            python-version: "3.11"  # TODO: bump to 3.12 when numba 0.59 is released
+            python-version: "3.12"
             fast-compile: 0
             float32: 0
             part: "tests/link/numba"