NaN-proof rectangle_perimeter

[lagru]

Description

Address #7114.

Checklist

• A descriptive but concise pull request title
• Docstrings for all functions
• Unit tests
• A gallery example in ./doc/examples for new features
• Contribution guide is followed

Release note

Summarize the introduced changes in the code block below in one or a few sentences. The
summary will be included in the next release notes automatically:

...

[github-actions]

Hello scikit-image core devs! There hasn't been any activity on this PR for more than 180 days. I have marked it as "dormant" to make it easy to find.
To our contributors, thank you for your contribution and apologies if this contribution fell through the cracks! Hopefully this ping will help bring some fresh attention to the review. If you need help, you can always reach out on our forum
If you think that this PR is no longer relevant, you may close it, or we may do it at some point (either way, it will be done manually). If you think the PR is valuable but you no longer have the bandwidth to update it, please let us know, so that someone can take it over. 🙏