upgrade go client and prometheus exporter

[AlexFenlon]

Proposed changes

Update go client from v1.3 to v2.1 and prometheus exporter from v1.3 to v1.4 for upcoming r33 changes

added logger from slog to pre-exisiting uses too as we now have slog imported.

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

[codecov]

Codecov Report

Attention: Patch coverage is 22.22222% with 7 lines in your changes missing coverage. Please review.

Project coverage is 52.96%. Comparing base (7c1e6c1) to head (73c503f).
Report is 5 commits behind head on main.

Files with missing lines	Patch %	Lines
internal/nginx/manager.go	0.00%	5 Missing ⚠️
cmd/nginx-ingress/main.go	0.00%	1 Missing ⚠️
internal/metrics/listener.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #6916      +/-   ##
==========================================
- Coverage   53.15%   52.96%   -0.19%     
==========================================
  Files          88       88              
  Lines       20396    20591     +195     
==========================================
+ Hits        10842    10907      +65     
- Misses       9111     9237     +126     
- Partials      443      447       +4     

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