refactor(typing): add @types/async and fix typing for its usage

[MasterOdin]

This adds @types/async and fixes an incompatible type that was being passed to it (it requires a concrete usage of interval and times, which is provided via the use of extend where the CheckParams interface is used.

Checklist

• npm test passes (tip: npm run autofix can correct most style issues)

[codecov-io]

Codecov Report

Merging #972 into release-v5-rc2 will increase coverage by 11.11%.
The diff coverage is n/a.

@@                 Coverage Diff                 @@
##           release-v5-rc2     #972       +/-   ##
===================================================
+ Coverage           77.77%   88.88%   +11.11%     
===================================================
  Files                   1        1               
  Lines                   9        9               
  Branches                2        2               
===================================================
+ Hits                    7        8        +1     
+ Misses                  2        1        -1

Impacted Files	Coverage Δ
test/resources/auth_helper.js	88.88% <0%> (+11.11%)	⬆️

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[germanattanasio]

@MasterOdin Thanks for the PR, I tried to look you up and found that your website is down http://www.mpeveler.com.

[dpopp07]

Looks good, thanks! 👍

[MasterOdin]

@germanattanasio Yeah, I keep meaning to find a day to re-setup my entire server after I borked it which had my site. In the meantime, I've put up a static site based out of github to make https://mpeveler.com accessible again.