Revert "Amend numpy-version for test matrix"

This reverts commit 2fa4e49.

Author: leehart

.github/workflows/tests.yml

@@ -10,10 +10,13 @@ jobs:
   tests:
     strategy:
       fail-fast: true
-      matrix: # See pyproject.toml
+      matrix:
         python-version: ["3.10", "3.11", "3.12"]
         numpy-version:
-          - "numpy>=2.0.0,<2.2.0" # 23-Jan-2026 Colab uses 2.0.2
+          - "numpy==1.26.4"  # current colab version
+          - "numpy~=2.0"  # 2.0 series
+          # numba (0.60.0) does not yet support numpy 2.1, disable this for now
+          # - "numpy~=2.1"  # 2.1 series
     runs-on: ubuntu-latest
 
     steps: