doc: remove old console note

This should not be important anymore in newer docs. The change is
also documented in the "changed" part of the function.

PR-URL: #17707
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/console.md

@@ -402,11 +402,6 @@ console.timeEnd('100-elements');
 // prints 100-elements: 225.438ms
 ```
 
-*Note*: As of Node.js v6.0.0, `console.timeEnd()` deletes the timer to avoid
-leaking it. On older versions, the timer persisted. This allowed
-`console.timeEnd()` to be called multiple times for the same label. This
-functionality was unintended and is no longer supported.
-
 ### console.trace([message][, ...args])
 <!-- YAML
 added: v0.1.104