refactor: replace glog in metrics & telemetry packages

[pdabelf5]

Proposed changes

Replace glog with slog in metrics & telemetry packages for:

• metrics/collectors/latency.go
• metrics/collectors/processes.go
• metrics/listener.go
• metrics/syslog_listener.go
• telemetry/collector.go

NOTE:

GLog Levels	Slog Levels
glog.V(3).Infof()	log.Debugf()
glog.V(3).Info()	log.Debug()
glog.V(2).Infof()	log.Debugf()
glog.V(2).Info()	log.Debugf()
glog.Infof()	log.Infof()
glog.Info()	log.Info()
glog.Warningf()	log.Warnf()
glog.Warning()	log.Warn()
glog.Errorf()	log.Errorf()
glog.Error()	log.Error()
glog.Fatalf()	log.Fatalf()
glog.Fatal()	log.Fatal()

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork

[AlexFenlon]

nil pointer for tests in collector_test.go - specifically anything that uses CollectorConfig

so please add "Context: context.Background(), " to each CollectorConfig to fix this issue.

Just needs to be updated with some recent changes from main - will do soon.

[codecov]

Codecov Report

Attention: Patch coverage is 18.75000% with 39 lines in your changes missing coverage. Please review.

Project coverage is 53.24%. Comparing base (62642a5) to head (22d2bc5).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/metrics/listener.go	0.00%	13 Missing ⚠️
internal/metrics/syslog_listener.go	0.00%	7 Missing ⚠️
internal/telemetry/collector.go	60.00%	6 Missing ⚠️
cmd/nginx-ingress/main.go	0.00%	5 Missing ⚠️
internal/metrics/collectors/latency.go	0.00%	5 Missing ⚠️
internal/metrics/collectors/processes.go	0.00%	3 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6587      +/-   ##
==========================================
- Coverage   53.28%   53.24%   -0.04%     
==========================================
  Files          87       87              
  Lines       16255    16262       +7     
==========================================
- Hits         8661     8659       -2     
- Misses       7181     7188       +7     
- Partials      413      415       +2     

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