fix(ci): correct path to test-npm-packages script

The npm package test script is located at scripts/npm/test-npm-packages.mjs,
not scripts/test-npm-packages.mjs.

Author: jdalton

.github/workflows/_local-not-for-reuse-ci.yml

@@ -48,4 +48,4 @@ jobs:
         run: pnpm run build
 
       - name: Run npm package tests
-        run: node scripts/test-npm-packages.mjs
+        run: node scripts/npm/test-npm-packages.mjs