fix: await http response in AWS EKS detector

[vreynolds]

Which problem is this PR solving?

• Initially, I was just trying to run the test suite, and happened to be using node 15. Uncovered a couple issues with the EKS detector/test
• Fixes Tests failing in tip of master #1776

Short description of the changes

• test suite was failing on node 15 because it no longer allows unhandled promise rejections
  • this was due to not awaiting a promise response from _isEks in the detector, so the if block was never evaluating the result of the call
• "unsuccessful" test cases were noop (error assertions never executed), because detect wraps itself in a try/catch, and never throws
  • updated those test cases to document current behavior
  • fixed the flipped test names

[linux-foundation-easycla]

The committers are authorized under a signed CLA.

• ✅ Vera Reynolds (7e936e9)

[codecov]

Codecov Report

Merging #2076 (e8436c7) into main (64c8ef5) will increase coverage by 0.01%.
The diff coverage is 100.00%.

❗ Current head e8436c7 differs from pull request most recent head 9d7209e. Consider uploading reports for the commit 9d7209e to get more accurate results

@@            Coverage Diff             @@
##             main    #2076      +/-   ##
==========================================
+ Coverage   92.72%   92.74%   +0.01%     
==========================================
  Files         137      137              
  Lines        5048     5048              
  Branches     1054     1054              
==========================================
+ Hits         4681     4682       +1     
+ Misses        367      366       -1     

Impacted Files	Coverage Δ
...ource-detector-aws/src/detectors/AwsEksDetector.ts	91.13% <100.00%> (+1.26%)	⬆️

[dyladan]

/cc @KKelvinLo original package author

/cc @willarmiros current AWS contact

[willarmiros]

lgtm