chore: guard unit-test.sh from being invoked by users

[aldy505]

Although I only seen one user reported this destroyed their self-hosted instance, and I initially thought to move the script elsewhere, I suppose this is a good alternative to really guard it.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.51%. Comparing base (a9a9148) to head (d676f08).
⚠️ Report is 3 commits behind head on master.
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4085   +/-   ##
=======================================
  Coverage   99.51%   99.51%           
=======================================
  Files           3        3           
  Lines         207      207           
=======================================
  Hits          206      206           
  Misses          1        1           

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