[TDR] Remove TODOs linked to issue 41256876.

This is an AI-generated dead TODOs removal. Please review to ensure this change is correct and safe. See go/dead-todo-removal-agent for more info.

The TODO comment requested multi-display support for touch exclusion zones. The associated bug, crbug.com/41256876, was marked as FIXED after a CL was submitted to convert the touch controller's logic from using display-specific coordinates to using screen-wide coordinates. This change resolves the issue described in the TODO, making the comment obsolete.

Bug: 41256876
Change-Id: I6af24aa8a08e82d405126831d4435ad4a061a50b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7095159
Auto-Submit: Tomasz Lichoń <lichon@google.com>
Reviewed-by: David Tseng <dtseng@chromium.org>
Commit-Queue: Katie Dektar <katie@chromium.org>
Reviewed-by: Katie Dektar <katie@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1539452}