Migrate from Zod v3 to v4 (#14639)

Closes [#1526](https://github.com/twentyhq/core-team-issues/issues/1526)

---------

Co-authored-by: Félix Malfait <felix@twenty.com>
Co-authored-by: Félix Malfait <felix.malfait@gmail.com>

packages/twenty-shared/src/workflow/schemas/webhook-trigger-schema.ts

@@ -0,0 +1,19 @@
+import { z } from 'zod';
+import { baseTriggerSchema } from './base-trigger-schema';
+
+export const workflowWebhookTriggerSchema = baseTriggerSchema.extend({
+  type: z.literal('WEBHOOK'),
+  settings: z.discriminatedUnion('httpMethod', [
+    z.object({
+      outputSchema: z.looseObject({}),
+      httpMethod: z.literal('GET'),
+      authentication: z.literal('API_KEY').nullable(),
+    }),
+    z.object({
+      outputSchema: z.looseObject({}),
+      httpMethod: z.literal('POST'),
+      expectedBody: z.looseObject({}),
+      authentication: z.literal('API_KEY').nullable(),
+    }),
+  ]),
+});