[BUILD] Fix protoc searching with non-imported protobuf::protoc target

[owent]

Fixes #2360

Changes

Please provide a brief description of the changes here.

• Fix protoc searching with non-imported protobuf::protoc target.

For significant contributions please make sure you have completed the following items:

• CHANGELOG.md updated for non-trivial changes
• Unit tests have been added
• Changes in public API reviewed

[codecov]

Codecov Report

Merging #2362 (371841d) into main (2c4b2a9) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #2362   +/-   ##
=======================================
  Coverage   87.41%   87.41%           
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  Files         199      199           
  Lines        6018     6018           
=======================================
  Hits         5260     5260           
  Misses        758      758           

[andremarianiello]

I filed #2360 and this fix worked for me. I would like to see it merged when possible. Thanks for the fix!

[marcalff]

LGTM, and fix tested by reporter.

Thanks for the fix.