chore: fix some sonar warnings

[thomaspoignant]

Description

fix some sonar warnings

Checklist

• I have tested this code
• I have followed the contributing guide

[netlify]

✅ Deploy Preview for go-feature-flag-doc-preview canceled.

Name	Link
🔨 Latest commit	4668bef
🔍 Latest deploy log	https://app.netlify.com/projects/go-feature-flag-doc-preview/deploys/692e962d5edc36000896ace2

[netlify]

✅ Deploy Preview for go-feature-flag-doc-preview canceled.

Name	Link
🔨 Latest commit	32b7b55
🔍 Latest deploy log	https://app.netlify.com/projects/go-feature-flag-doc-preview/deploys/693bd6d0d4be800008dcff6a

[codecov]

Codecov Report

❌ Patch coverage is 86.95652% with 9 lines in your changes missing coverage. Please review.
✅ Project coverage is 85.31%. Comparing base (3a7ca53) to head (32b7b55).
⚠️ Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
cmd/cli/evaluate/evaluate.go	66.66%	1 Missing and 1 partial ⚠️
cmd/cli/generate/manifest/manifest_cmd.go	33.33%	1 Missing and 1 partial ⚠️
cmd/cli/helper/print_output.go	33.33%	1 Missing and 1 partial ⚠️
cmd/relayproxy/api/server.go	88.88%	1 Missing ⚠️
cmd/relayproxy/config/config_validator.go	50.00%	1 Missing ⚠️
cmd/relayproxy/main.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4391      +/-   ##
==========================================
- Coverage   85.33%   85.31%   -0.03%     
==========================================
  Files         145      145              
  Lines        6056     6059       +3     
==========================================
+ Hits         5168     5169       +1     
+ Misses        663      661       -2     
- Partials      225      229       +4     

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[sonarqubecloud]

Quality Gate passed

Issues
2 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud