[TDR] Remove TODOs linked to issue 40910554.

This is an AI-generated dead TODOs removal. Please review to ensure this
change is correct. This CL was verified by the CL owner before sending
it out. See http://go/dead-todo-removal-agent for more info.

The TODO requested a refactoring to remove circular calls, which was
completed by removing the registerTrackForLevel method from the
CompatibilityTracksAppender class, as confirmed by the bug's resolution
and analysis of the current source code.

Change-Id: I64cd40d417195e6e5e3d80b61640d5d88e2a2373
Bug: 40910554
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/7231687
Reviewed-by: Benedikt Meurer <[email protected]>
Reviewed-by: Jack Franklin <[email protected]>
Commit-Queue: Benedikt Meurer <[email protected]>

Author: Kuba Mikulski

front_end/panels/timeline/CompatibilityTracksAppender.ts

@@ -510,7 +510,6 @@ export class CompatibilityTracksAppender {
    * @returns the index of the event in all events to be rendered in the flamechart.
    */
   appendEventAtLevel(event: Trace.Types.Events.Event, level: number, appender: TrackAppender): number {
-    // TODO(crbug.com/1442454) Figure out how to avoid the circular calls.
     this.#trackForLevel.set(level, appender);
     const index = this.#entryData.length;
     this.#entryData.push(event);