Support Skill in manifest (#18092)

# Introduction
Support skill in manifest, pre-requisite for the twenty standard app
migration

packages/twenty-sdk/src/cli/__tests__/apps/rich-app/__integration__/app-dev/expected-manifest.ts

@@ -18,6 +18,7 @@ export const EXPECTED_MANIFEST: Manifest = {
       fileType: 'png',
     },
   ],
+  skills: [],
   application: {
     applicationVariables: {
       DEFAULT_RECIPIENT_NAME: {

packages/twenty-sdk/src/cli/__tests__/apps/root-app/__integration__/app-dev/expected-manifest.ts

@@ -13,6 +13,7 @@ export const EXPECTED_MANIFEST: Manifest = {
     yarnLockChecksum: 'd41d8cd98f00b204e9800998ecf8427e',
     apiClientChecksum: null,
   },
+  skills: [],
   publicAssets: [],
   fields: [],
   objects: [