Adds node18 to node_version matrix to enable node18 test

[Keimille]

Which problem is this PR solving?
Added node version to matrix in unit-test.yml to extend tests to node 18

Fixes #2935

Short description of the changes
Type of change
Adds node 18 version to unit-test.yml

How Has This Been Tested?
Tested changes in forked repo to ensure desired results in workflow.

[codecov]

Codecov Report

Merging #2949 (4950d63) into main (ddb0775) will not change coverage.
The diff coverage is n/a.

❗ Current head 4950d63 differs from pull request most recent head 341bfd5. Consider uploading reports for the commit 341bfd5 to get more accurate results

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  Files         185      185           
  Lines        6089     6089           
  Branches     1304     1304           
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  Hits         5661     5661           
  Misses        428      428           

[Flarna]

Seems tests for node 18 don't run because there are no node.js pre-built binaries for grpc and it doesn't compile.

I think we should skip the effected tests as grpc is deprecated in favor of @grpc/grpc-js and therefore this problem will not go away.

[Keimille]

Seems tests for node 18 don't run because there are no node.js pre-built binaries for grpc and it doesn't compile.

I think we should skip the effected tests as grpc is deprecated in favor of @grpc/grpc-js and therefore this problem will not go away.

Yep, mentioned this in the issue comments, but submitted the PR to raise the issue.

[dyladan]

grpc is only used by the instrumentation-grpc. We should simply skip testing that package on the node 18 tests as grpc package doesn't support node 18 and the instrumentatation-grpc package is only useful if the grpc package is in use.

[Flarna]

instrumentation-grpc takes additionally care of @grpc/grpc-js which is the replacement of grpc and I think we should test it.

[legendecas]

Thank you for your work on this! However, as #3048 has added the v18.x testing coverage, I'm closing this.