Move lint script to sitting under npm-run-all, to allow parallel ru…

…nners (#517)

* Move lint script to sitting under `npm-run-all`, to allow parallel runners

* Ensure the GitHub Action runners uses the combined linter to cut down on its runtime as well.

.github/workflows/lint-js-css.yml

@@ -34,8 +34,5 @@ jobs:
             - name: Install Dependencies
               run: npm ci
 
-            - name: Lint CSS
-              run: npm run lint:css
-
-            - name: Lint JS
-              run: npm run lint:js
+            - name: Run linters
+              run: npm run lint

package.json

@@ -25,6 +25,7 @@
 		"eslint-plugin-prettier": "^5.1.3",
 		"husky": "^9.0.11",
 		"lint-staged": "^15.2.7",
+		"npm-run-all": "^4.1.5",
 		"postcss": "^8.4.38",
 		"postcss-custom-media": "^10.0.6",
 		"postcss-discard-comments": "^7.0.1",
@@ -47,7 +48,7 @@
 		"clean": "turbo run clean && rm -rf node_modules",
 		"format": "prettier --write .",
 		"check-engines": "wp-scripts check-engines",
-		"lint": "npm run lint:js && npm run lint:css && npm run lint:format",
+		"lint": "npm-run-all --parallel lint:js lint:css lint:format",
 		"lint:css": "wp-scripts lint-style",
 		"lint:js": "wp-scripts lint-js",
 		"lint:format": "prettier --check .",