🐛 fix: treat case for possible timer memory leak

[luk3skyw4lker]

Description

It was reported in the gopsutil a possible memory leak for the Sleep function, the fix is to in case of the timer being cancelled by the context, checking if the timer isn't stopped and stoping it.

Fixes #2482

Type of change

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• Bug fix (non-breaking change which fixes an issue)

Checklist:

• For new functionalities I follow the inspiration of the express js framework and built them similar in usage
• I have performed a self-review of my own code
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• I tried to make my code as fast as possible with as few allocations as possible
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[gaby]

This is an upstream fix from here: shirou/gopsutil#1475

[gaby]

LGTM

[gaby]

Thanks! @luk3skyw4lker

[sixcolors]

LGTM!

see: shirou/gopsutil#1475

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