fix: Stop EKS detector erroring outside of K8S

[bodgit]

This is a simple fix to stop the EKS detector erroring when run outside of Kubernetes.

Fixes #7477

[dashpole]

Can you add a unit test?

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 81.5%. Comparing base (be730df) to head (a36b6e8).
Report is 1 commits behind head on main.

Additional details and impacted files

@@          Coverage Diff          @@
##            main   #7483   +/-   ##
=====================================
  Coverage   81.5%   81.5%           
=====================================
  Files        198     198           
  Lines      17961   17963    +2     
=====================================
+ Hits       14643   14647    +4     
+ Misses      2918    2917    -1     
+ Partials     400     399    -1     

Files with missing lines	Coverage Δ
detectors/aws/eks/detector.go	39.3% <100.0%> (+3.6%)	⬆️

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