ci: Add workflow to automatically run npm audit fix weekly

[mofojed]

• Scheduled to run every Thursday morning at 6am UTC (2am ET)
• Opens a PR automatically
• PR still needs to be reviewed/approved

[codecov]

Codecov Report

Merging #1422 (b7811f0) into main (29a7d8d) will not change coverage.
Report is 1 commits behind head on main.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #1422   +/-   ##
=======================================
  Coverage   45.71%   45.71%           
=======================================
  Files         511      511           
  Lines       35065    35065           
  Branches     8767     8767           
=======================================
  Hits        16029    16029           
  Misses      18985    18985           
  Partials       51       51           

Flag	Coverage Δ
unit	45.71% <ø> (ø)

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[mattrunyon]

Did you test this or is this action sourced from somewhere?

[mofojed]

@mattrunyon Tested this here: mofojed#20