refactor(amazonq): remove duplicate metric aws#935

## Problem
`codeTransform_jobIsStartedFromChatPrompt` is unused, and we already
have `codeTransform_initiateTransform`

## Solution
Remove

Author: dhasani23

telemetry/definitions/commonDefinitions.json

@@ -4109,20 +4109,6 @@
                 }
             ]
         },
-        {
-            "name": "codeTransform_jobIsStartedFromChatPrompt",
-            "description": "The user initiates a transform job from the Amazon Q chat prompt.",
-            "metadata": [
-                {
-                    "type": "codeTransformSessionId",
-                    "required": true
-                },
-                {
-                    "type": "credentialSourceId",
-                    "required": false
-                }
-            ]
-        },
         {
             "name": "codeTransform_jobStart",
             "description": "Transform job started for uploaded project.",