Add Python 3.12 to CI

I guess that's the latest version nowadays.

Author: asmeurer

.github/workflows/array-api-tests.yml

@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.9', '3.10', '3.11']
+        python-version: ['3.9', '3.10', '3.11', '3.12']
         numpy-version: ['1.26', 'dev']
         exclude:
           - python-version: '3.8'

.github/workflows/tests.yml

@@ -5,7 +5,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        python-version: ['3.9', '3.10', '3.11']
+        python-version: ['3.9', '3.10', '3.11', '3.12']
         numpy-version: ['1.26', 'dev']
         exclude:
           - python-version: '3.8'