fix: unpin version of copywrite

[ansgarm]

0.16.6 has been released which fixes the problem why we pinned this version in #3150

Related issue

Fixes #

Description

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Checklist

• I have updated the PR title to match CDKTF's style guide
• I have run the linter on my code locally
• I have performed a self-review of my code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation if applicable
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works if applicable
• New and existing unit tests pass locally with my changes

[github-actions]

I'm going to lock this pull request because it has been closed for 30 days. This helps our maintainers find and focus on the active issues. If you've found a problem that seems related to this change, please open a new issue and complete the issue template so we can capture all the details necessary to investigate further.