fix: update lerna exec command to run via npx

Author: sghoweri

package.json

@@ -23,7 +23,7 @@
     "start": "cd docs-site && yarn run start",
     "build": "cd docs-site && yarn run build:prod",
     "setup": "yarn",
-    "setup:php": "lerna exec --scope @bolt/twig-renderer --scope @bolt/drupal-twig-extensions --scope @bolt/core-php -- yarn run setup",
+    "setup:php": "npx lerna exec --scope @bolt/twig-renderer --scope @bolt/drupal-twig-extensions --scope @bolt/core-php -- yarn run setup",
     "setup:quick": "yarn install --production",
     "setup:full": "yarn --force",
     "deploy": "./scripts/deploy.js",