ci: Block all external network calls in tests (no-changelog) (#4930)

* setup nock to prevent tests from making any external requests

* mock all calls to posthog sdk

packages/cli/jest.config.js

@@ -4,6 +4,7 @@ module.exports = {
 	testEnvironmentOptions: {
 		url: 'http://localhost/',
 	},
+	globalSetup: '<rootDir>/test/setup.ts',
 	globalTeardown: '<rootDir>/test/teardown.ts',
 	moduleNameMapper: {
 		'^@/(.*)$': '<rootDir>/src/$1',