fix(jest): use --rootDir option (#8754)

package.json

@@ -44,10 +44,10 @@
     "stylelint": "stylelint \"**/*.scss\"",
     "test": "yarn prettier-check && yarn test:client && yarn test:kumascript && yarn test:content && yarn test:testing",
     "test:client": "cd client && tsc --noEmit && cross-env NODE_ENV=test BABEL_ENV=test PUBLIC_URL='' node scripts/test.js --env=jsdom",
-    "test:content": "yarn jest content",
+    "test:content": "yarn jest --rootDir content",
     "test:developing": "cross-env CONTENT_ROOT=mdn/content/files TESTING_DEVELOPING=true playwright test developing",
     "test:headless": "playwright test headless",
-    "test:kumascript": "yarn jest kumascript --env=node",
+    "test:kumascript": "yarn jest --rootDir kumascript --env=node",
     "test:prepare": "yarn build:prepare && yarn build && yarn start:static-server",
     "test:testing": "yarn jest --rootDir testing",
     "tool": "ts-node tool/cli.ts",