refactor(test-utils): Migrate away from deprecated addSpanProcessor

[chancancode]

This migrates from the deprecated addSpanProcessor method to the constructor option in preparation for the upcoming SDK 2.0 release.

This commit migrates the runtime code in the test-utils package and should be included in the package's CHANGELOG.

Ref #2645 (cc @pichlermarc)

[chancancode]

https://github.com/open-telemetry/opentelemetry-js-contrib/blob/main/.github/component-label-map.yml#L5

I suppose these rules are to ping maintainers to look at any changes to the shared test utils, which is fair enough (though this is really minor).

However, for the purpose of lerna-changelog, the pkg labels are definitely wrong. That should be fixed before merging.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.79%. Comparing base (e57f3e4) to head (31dd654).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2660   +/-   ##
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  Coverage   90.79%   90.79%           
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  Files         169      169           
  Lines        8061     8061           
  Branches     1646     1646           
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  Hits         7319     7319           
  Misses        742      742           

[pichlermarc]

Looks good, thanks - I've changed the title to be refactor this way it won't show up as a bugfix in the changelog.

[pichlermarc]

The package lables won't affect the changelog - the entry generated will only be for contrib-test-utils :)
We use them to determine which tests need to be run and to give an overview of which packages in the repo are affected by the change.