opt: fix the potential goroutine leak after calling `Release()`

…rom Release method

name: Refactor Release Methods about: Call cleanup functions when Release() is called. title: '' labels: '' assignees: ''

1. Are you opening this pull request for bug-fixs, optimizations or new feature?

Bug fix.

2. Please describe how these code changes achieve your intention.

By moving stopTicktock and stopPurge into Release() methods from ReleaseTimeout(), these functions will be stopped when Release() is called.

3. Please link to the relevant issues (if any).

https://github.com/panjf2000/ants/issues/244

4. Which documentation changes (if any) need to be made/updated because of this PR?

4. Checklist

[x] I have squashed all insignificant commits.
[x] I have commented my code for explaining package types, values, functions, and non-obvious lines.
[x] I have written unit tests and verified that all tests passes (if needed).
[x] I have documented feature info on the README (only when this PR is adding a new feature).
[x] (optional) I am willing to help maintain this change if there are issues with it later.

Codecov Report

Patch coverage: 100.00% and project coverage change: +0.01 :tada:

Comparison is base (45a0390) 92.46% compared to head (3d949cf) 92.48%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## dev #287 +/- ## ========================================== + Coverage 92.46% 92.48% +0.01% ========================================== Files 9 9 Lines 770 772 +2 ========================================== + Hits 712 714 +2 Misses 44 44 Partials 14 14 ``` | Flag | Coverage Δ | | |---|---|---| | unittests | `92.48% <100.00%> (+0.01%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Andy+Pan#carryforward-flags-in-the-pull-request-comment) to find out more. | [Impacted Files](https://app.codecov.io/gh/panjf2000/ants/pull/287?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Andy+Pan) | Coverage Δ | | |---|---|---| | [pool.go](https://app.codecov.io/gh/panjf2000/ants/pull/287?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Andy+Pan#diff-cG9vbC5nbw==) | `91.25% <100.00%> (+0.03%)` | :arrow_up: | | [pool\_func.go](https://app.codecov.io/gh/panjf2000/ants/pull/287?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Andy+Pan#diff-cG9vbF9mdW5jLmdv) | `90.12% <100.00%> (+0.04%)` | :arrow_up: |

:umbrella: View full report in Codecov by Sentry.
:loudspeaker: Do you have feedback about the report comment? Let us know in this issue.

panjf2000 / ants