Fix exporter-{jaeger,otlp,zipkin} install paths

[musicinmybrain]

These “convenience” packages were incorrectly installed in site-packages/src, although the actual implementation packages they depended on were installed in the correct paths (which is probably why this was not noticed sooner).

Please see #2020 for full details.

Description

Adds the following to the setup.cfg file for each of these packages—previously missing as compared to other opentelmetry packages:

[options]
package_dir=
    =src
 
[options.packages.find]
where = src

Fixes #2020

Type of change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

I’ve been carrying this patch downstream in Fedora Linux, where I find it fixes the install path as expected.

You can probably best verify this by using your usual workflow to install the patched opentelemetry-exporter-jaeger, opentelemetry-exporter-otlp, and opentelemetry-exporter-zipkin (separately or all at once) into a virtualenv, then looking inside the virtualenv directory to verify that no lib/python*/site-packages/src directory exists. See #2020 for details.

Does This PR Require a Contrib Repo Change?

Answer the following question based on these examples of changes that would require a Contrib Repo Change:

• The OTel specification has changed which prompted this PR to update the method interfaces of opentelemetry-api/ or opentelemetry-sdk/

• The method interfaces of test/util have changed

• Scripts in scripts/ that were copied over to the Contrib repo have changed

• Configuration files that were copied over to the Contrib repo have changed (when consistency between repositories is applicable) such as in

  • pyproject.toml
  • isort.cfg
  • .flake8

• When a new .github/CODEOWNER is added

• Major changes to project information, such as in:

  • README.md
  • CONTRIBUTING.md

• Yes. - Link to PR:

• No.

Checklist:

• Followed the style guidelines of this project
• Changelogs have been updated
• Unit tests have been added not applicable
• Documentation has been updated not applicable

[musicinmybrain]

Force-pushed with a changelog entry now that I have a PR number.