ci: move runner signing configurations into the circleci directory

[zimeg]

Summary

This PR moves configurations for the CircleCI runner into the .circleci path to avoid confusing source code and build logic 🤖

Notes

• A corresponding PR will soon exist for the runner to find these new paths!

Requirements

• I've read and understood the Contributing Guidelines and have done my best effort to follow them.
• I've read and agree to the Code of Conduct.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 63.46%. Comparing base (d1372cc) to head (0650dfb).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #120   +/-   ##
=======================================
  Coverage   63.45%   63.46%           
=======================================
  Files         212      212           
  Lines       22341    22341           
=======================================
+ Hits        14176    14178    +2     
+ Misses       7073     7071    -2     
  Partials     1092     1092           

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[mwbrooks]

✅ Love it! Cleans up our root directory and makes it easier to find all CircleCI related files.

👥 I'd like to get @cchensh's review before we merge this (once the corresponding PR is up to find these files).

[zimeg]

@mwbrooks Heh thanks! I was most hopeful for this to be a welcomed change 🙏 ✨

I'll hold off on merging it for now and have opened a corresponding PR in the runner's repo but I cannot link it here! 🔗

In the meantime I am looking into signing builds for #114 - this is what motivated the update most! 🎁

[zimeg]

@mwbrooks Thanks for reviewing! 👾 ✨

@cchensh and I are updating the runner now so I will merge this and test a code signing job with the latest updates 🫡