chore: reset test coverage package list

[qweeah]

What this PR does / why we need it:
Before this change, the nested $() in Makefile $(GO_EXE) list ./... | grep -v internal/testutils | tr '\n' ',' generates empty return value so -coverpkg is actually set to ''

Please check the following list:

• Does the affected code have corresponding tests, e.g. unit test, E2E test?
• Does this change require a documentation update?
• Does this introduce breaking changes that would require an announcement or bumping the major version?
• Do all new files have an appropriate license header?

[TerryHowe]

/lgtm

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 85.54%. Comparing base (7b966eb) to head (4d75b0c).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1482      +/-   ##
==========================================
+ Coverage   83.43%   85.54%   +2.10%     
==========================================
  Files         113      113              
  Lines        3936     3936              
==========================================
+ Hits         3284     3367      +83     
+ Misses        428      342      -86     
- Partials      224      227       +3     

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