chore(provisioner): support updated coder_ai_task resource (#20160)

Closes https://github.com/coder/internal/issues/978

- Introduce `CODER_TASK_ID` and `CODER_TASK_PROMPT` to the provisioner
environment
- Make use of new `app_id` field in provider, with a fallback to
`sidebar_app.id` for backwards compatibility

**For now** I've left the `taskPrompt` and `taskID` as a TODO as we do
not yet create these values.

provisionerd/proto/version.go

@@ -53,9 +53,13 @@ import "github.com/coder/coder/v2/apiversion"
 //
 // API v1.10:
 //   - Added new field `tooltip` in `App`
+//
+// API v1.11:
+//   - Added new fields `task_id` and `task_prompt` to `Manifest`.
+//   - Added new field `app_id` to `AITask`
 const (
 	CurrentMajor = 1
-	CurrentMinor = 10
+	CurrentMinor = 11
 )
 
 // CurrentVersion is the current provisionerd API version.