This pull request fixes a bug where setting "noUpdateNotifier": true in turbo.json did not suppress update notifications.
Turbo continued printing out-of-date version warnings regardless of the flag’s value.
What was happening
Even when users explicitly disabled update notifications using:
{ "noUpdateNotifier": true }
Turbo still displayed upgrade messages when the installed version was behind the latest available version.
This violated the expected behavior described in Issue #10940.
What this PR does:

• Ensures that when noUpdateNotifier is set to true, Turbo skips the update-notifier check entirely.
• Prevents unnecessary noise in CI pipelines and automated scripts.
• Restores expected behavior and aligns with Turbo’s configuration contract.

How I verified the fix:
Added "noUpdateNotifier": true to turbo.json.
Ran Turbo using an intentionally outdated version.
Confirmed that no update notification was printed.
Verified that notifications still appear when the flag is not set.

Linked Issue
Fixes: #10940