Certain scopes are excluded from the conventional_commits filter

[pataar]

Describe the bug
Some conventional_commits are not marked as conventional_commits. We're using scopes with underscores and those commits are not seen as conventional. This is valid though: https://github.com/conventional-commits/parser#the-grammar

To Reproduce
Steps to reproduce the behavior:

1. Create a new commit. For example: feat(my_feature): add the new 'my' feature
2. See that it's not included in the changelog when the conventional_commits config setting is true.

Expected behavior
It should be added as it's a valid conventional commit message.

System (please complete the following information):

• OS Information: not relevant
• Project Version: 0.4.0

Additional context
Add any other context about the problem here.

I think this problem occurs in the git-conventional dependency. I also made an issue there:
crate-ci/git-conventional#17