Don't output extraneous blank line when progress display is disabled

Type of changes

• Bug fix
• New feature
• Documentation / docstrings
• Tests
• Other

AI?

• AI was used to generate this PR

AI generated PRs may be accepted, but only if @willmcgugan has responded on an issue or discussion.

Checklist

• I've run the latest black with default args on new code.
• I've updated CHANGELOG.md and CONTRIBUTORS.md where appropriate (see note about typos above).
• I've added tests for new code.
• I accept that @willmcgugan may be pedantic in the code review.

Description

When creating a Progress with disabled=True, it still outputs a blank line on non interactive consoles. This PR adds an if not self.disable to the stop function, symmetrically to the start function.

Important: Link to an issue or discussion regarding these changes.

#110

@Domimueller85 Let me know if your comments were some kind of mistake. If I don't hear from you, I intend to ban you from the repo.