chore(instrumentation-grpc): drop support for grpc

[llc1123]

Which problem is this PR solving?

Dropped support for package grpc (not @grpc-js/grpc) due to deprecation.

Fixes #3780

Short description of the changes

• Removed grpc example.
• Dropped support of grpc instrumentation.
• Fixed a few eslint warnings in instrumentation-grpc

Type of change

Please delete options that are not relevant.

• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Existing tests

Checklist:

• Followed the style guidelines of this project
• Unit tests have been added
• Documentation has been updated

[codecov]

Codecov Report

Merging #3807 (ee3f1c8) into main (4a7091f) will decrease coverage by 0.09%.
The diff coverage is 100.00%.

❗ Current head ee3f1c8 differs from pull request most recent head 6159018. Consider uploading reports for the commit 6159018 to get more accurate results

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3807      +/-   ##
==========================================
- Coverage   92.98%   92.89%   -0.09%     
==========================================
  Files         300      297       -3     
  Lines        9104     8836     -268     
  Branches     1862     1814      -48     
==========================================
- Hits         8465     8208     -257     
+ Misses        639      628      -11     

Impacted Files	Coverage Δ
...elemetry-instrumentation-grpc/src/grpc-js/index.ts	92.74% <ø> (ø)
...emetry-instrumentation-grpc/src/instrumentation.ts	72.72% <ø> (-3.14%)	⬇️
...ry-instrumentation-grpc/src/grpc-js/clientUtils.ts	92.85% <100.00%> (ø)
...es/opentelemetry-instrumentation-grpc/src/utils.ts	82.69% <100.00%> (-11.54%)	⬇️

[dyladan]

LGTM % nit

[pichlermarc]

Thanks for removing this. 🙂

We discussed this change in the SIG meeting last week, and figured we would add a postinstall script first to the package to alert users that the grpc-native instrumentaiton is being removed as not to break people in an completely unexpected manner.

So we will hold off on merging this, add a postinstall script warning users that this is about to happen, release, then merge this PR.

[pichlermarc]

Current versions of instrumentation-grpc should now have a warning that this will be removed, so this PR should be safe to merge now - just one nit though + request to create a follow-up issue to refactor as some of the code that became unnecessary with this change.