Remove *.dist-info directories except entry_points.txt files.

[purple4reina]

What does this PR do?

No longer delete the entire contents of each *.dist-info directory. Keep any entry_point.txt files and remove the rest, leaving no empty directories.

Motivation

See #548

Testing Guidelines

Additional Notes

Types of Changes

• Bug fix
• New feature
• Breaking change
• Misc (docs, refactoring, dependency upgrade, etc.)

Check all that apply

• This PR's description is comprehensive
• This PR contains breaking changes that are documented in the description
• This PR introduces new APIs or parameters that are documented and unlikely to change in the foreseeable future
• This PR impacts documentation, and it has been updated (or a ticket has been logged)
• This PR's changes are covered by the automated tests
• This PR collects user input/sensitive content into Datadog
• This PR passes the integration tests (ask a Datadog member to run the tests)

[purple4reina]

I have confirmed that the error thrown by the following handler is fixed with this PR.

def handler(event, context):
    try:
        from opentelemetry import trace
    except ImportError:
        pass
    return 'ok'