detectors/kubeadm: add Kubeadm resource detector

[paulojmdias]

Ports the kubeadm resource detector from processor/resourcedetectionprocessor/internal/kubeadm in
opentelemetry-collector-contrib to a new standalone Go module go.opentelemetry.io/contrib/detectors/kubeadm.

Also registers the detector in detectors/autodetect as IDKubeadm ("kubeadm").

I'm proposing to be a codeowner of this detector as I am currently on the collector-contrib side.

Fixes #8954
Relates #8940

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 84.6%. Comparing base (b0f0785) to head (21bf828).
⚠️ Report is 4 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #9500   +/-   ##
=====================================
  Coverage   84.5%   84.6%           
=====================================
  Files        203     204    +1     
  Lines      16805   16880   +75     
=====================================
+ Hits       14215   14290   +75     
  Misses      2110    2110           
  Partials     480     480           

Files with missing lines	Coverage Δ
detectors/autodetect/autodetect.go	87.1% <100.0%> (+0.1%)	⬆️
detectors/kubeadm/kubeadm.go	100.0% <100.0%> (ø)

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