test: run sequentially rather than in parallel

the parallelization needs to happen within the GH containers instead

Author: ericapisani

package.json

@@ -11,7 +11,7 @@
     "prepare": "husky install node_modules/@netlify/eslint-config-node/.husky/",
     "test": "run-s format install:demo build:demo test:unit test:e2e",
     "test:unit": "jest",
-    "test:e2e": "run-p test:e2e:*",
+    "test:e2e": "run-s test:e2e:*",
     "test:e2e:v4": "cd plugin/test && ./v4-e2e-test.sh",
     "test:e2e:v5": "cd plugin/test && ./v5-e2e-test.sh",
     "format": "run-s format:check-fix:*",