run go fix to modernize the codebase

[arner]

https://go.dev/blog/gofix

[codecov]

Codecov Report

❌ Patch coverage is 57.14286% with 3 lines in your changes missing coverage. Please review.
✅ Project coverage is 22.75%. Comparing base (6bac0b5) to head (862dbed).

Files with missing lines	Patch %	Lines
endorser/storage/lightkvs.go	0.00%	2 Missing ⚠️
gateway/core/txqueue_v2.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #268      +/-   ##
==========================================
- Coverage   22.77%   22.75%   -0.02%     
==========================================
  Files          71       71              
  Lines       10439    10434       -5     
==========================================
- Hits         2377     2374       -3     
+ Misses       7787     7786       -1     
+ Partials      275      274       -1     

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[kushnireyal]

Looks good. Needs a rebase and a re-run