chore: Install numpy before running tests

Author: paxcodes

tox.ini

@@ -16,6 +16,7 @@ deps =
     django5.1: Django>=5.1,<5.2
     coverage
 commands =
+    pip install numpy
     # Use local clickhouse_backend package so that coverage works properly.
     pip install -e .
     coverage run tests/runtests.py --debug-sql {posargs}