Deprecate Probability field on Opportunity (#6207)

Closes #5735.
The field probability on opportunity will -
- stop being created for new workspaces (after this PR is merged)
- have "isCustom" value set to true and be displayed as such in the
settings (after this PR is merged + sync-metadata is run on workspace)
- still show in the views (all the time)

This field is deprecated as a standard field but not replaced by another
one, so we are not adding the `(deprecated)` suffix in the label.

packages/twenty-front/src/testing/mock-data/generated/standard-metadata-query-result.ts

@@ -5567,29 +5567,6 @@ export const mockedStandardObjectMetadataQueryResult: ObjectMetadataItemsQuery =
 								"toRelationMetadata": null
 							}
 						},
-						{
-							"__typename": "fieldEdge",
-							"node": {
-								"__typename": "field",
-								"id": "dd99cf8d-a10c-4d41-8469-6b5e03e5ae2e",
-								"type": "TEXT",
-								"name": "probability",
-								"label": "Probability",
-								"description": "Opportunity probability",
-								"icon": "IconProgressCheck",
-								"isCustom": false,
-								"isActive": true,
-								"isSystem": false,
-								"isNullable": false,
-								"createdAt": "2024-06-07T09:05:12.599Z",
-								"updatedAt": "2024-06-07T09:05:12.599Z",
-								"defaultValue": "'0'",
-								"options": null,
-								"relationDefinition": null,
-								"fromRelationMetadata": null,
-								"toRelationMetadata": null
-							}
-						},
 						{
 							"__typename": "fieldEdge",
 							"node": {