update npy_promotion_state during test

Author: briangow

.github/workflows/test.yml

@@ -8,9 +8,6 @@ on:
     branches:
       - main
 
-env:
-  NPY_PROMOTION_STATE: weak_and_warn
-
 jobs:
   test:
     name: Python ${{ matrix.python-version }} / ${{ matrix.os }} / ${{ matrix.numpy }}
@@ -40,6 +37,8 @@ jobs:
     name: Python 3.7 on Debian 11 i386
     runs-on: ubuntu-latest
     container: i386/debian:11
+    env:
+      NPY_PROMOTION_STATE: weak_and_warn
     steps:
       - name: Install dependencies
         run: |