Fix entry point scripts

[ofek]

Summary of changes

Fix to #2194 @jaraco

Is there a better way to inject just the package name? I thought that is what spec was.

Traceback (most recent call last):
  File "/opt/hostedtoolcache/Python/3.8.3/x64/bin/ddev", line 9, in <module>
    for entry_point in distribution('datadog-checks-dev==3.11.0').entry_points:
  File "/opt/hostedtoolcache/Python/3.8.3/x64/lib/python3.8/importlib/metadata.py", line 504, in distribution
    return Distribution.from_name(distribution_name)
  File "/opt/hostedtoolcache/Python/3.8.3/x64/lib/python3.8/importlib/metadata.py", line 177, in from_name
    raise PackageNotFoundError(name)
importlib.metadata.PackageNotFoundError: datadog-checks-dev==3.11.0

Pull Request Checklist

• Changes have tests
• News fragment added in changelog.d. See documentation for details

[cooperlees]

Many thanks for this fix. Just a thought on the test side. Pretty common use case I feel.