Add context to http calls

[lucacome]

Adds context to http calls that check config version.
This fixes a couple of linter errors:

internal/nginx/verify.go:40:27: (*net/http.Client).Get must not be called (noctx)
internal/nginx/manager.go:436:29: should rewrite http.NewRequestWithContext or add (*Request).WithContext (noctx)

[codecov-commenter]

Codecov Report

Merging #3233 (94ad8eb) into main (91f9da8) will decrease coverage by 0.02%.
The diff coverage is 33.33%.

@@            Coverage Diff             @@
##             main    #3233      +/-   ##
==========================================
- Coverage   52.58%   52.56%   -0.03%     
==========================================
  Files          59       59              
  Lines       16078    16088      +10     
==========================================
+ Hits         8454     8456       +2     
- Misses       7347     7354       +7     
- Partials      277      278       +1     

Impacted Files	Coverage Δ
internal/nginx/manager.go	0.00% <0.00%> (ø)
internal/nginx/verify.go	56.94% <62.50%> (+0.02%)	⬆️
...ternal/k8s/appprotect/app_protect_configuration.go	86.16% <0.00%> (-0.58%)	⬇️

📣 We’re building smart automated test selection to slash your CI/CD build times. Learn more