fix: Remove company field from conversation schema in v2.15 spec

The company field on conversations is only available in the Unstable API
version. It was incorrectly included in the v2.15 spec.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: markdennis22

descriptions/2.15/api.intercom.io.yaml

@@ -17472,10 +17472,6 @@ components:
           description: The id of the team assigned to the conversation. If it's not
             assigned to a team it will return null.
           example: '5017691'
-        company:
-          "$ref": "#/components/schemas/company"
-          nullable: true
-          description: The company associated with the conversation.
         tags:
           "$ref": "#/components/schemas/tags"
         conversation_rating:
@@ -17586,10 +17582,6 @@ components:
           description: The id of the team assigned to the conversation. If it's not
             assigned to a team it will return null.
           example: '5017691'
-        company:
-          "$ref": "#/components/schemas/company"
-          nullable: true
-          description: The company associated with the conversation.
         tags:
           "$ref": "#/components/schemas/tags"
         conversation_rating: