Fix CNA postinstall script

Author: connor-baer

packages/cna-template/template/package.json

@@ -9,7 +9,7 @@
     "start": "next start",
     "test": "jest --watch",
     "test:ci": "mkdir -p __reports__ && jest --ci --coverage --runInBand --json --outputFile=__reports__/jest-results.json --reporters default --reporters \"github-actions\"",
-    "postinstall": "npm run foundry init -- --presets lint; echo \"Remove the postinstall script from the package.json file after setting up Foundry.\""
+    "postinstall": "npx foundry init -- --presets lint; echo \"Remove the postinstall script from the package.json file after setting up Foundry.\""
   },
   "dependencies": {
     "@emotion/css": "^11.10.5",