Don't run NumPy 1.21 in Python 3.11

Author: asmeurer

.github/workflows/array-api-tests-numpy-1-21.yml

@@ -9,3 +9,7 @@ jobs:
       package-name: numpy
       package-version: '== 1.21.*'
       xfails-file-extra: '-1-21'
+
+    strategy:
+      matrix:
+        python-version: ['3.8', '3.9', '3.10']