Fix links to spec schemas

[edgarrmondragon]

See #1889 (comment).

The links in https://python-packaging-user-guide--1910.org.readthedocs.build/en/1910/specifications/schemas/ are working now :)

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📚 Documentation preview 📚: https://python-packaging-user-guide--1910.org.readthedocs.build/en/1910/

[hugovk]

Thank you!

[webknjaz]

Thanks!

[webknjaz]

Looks like we need another ignore for https://developer.hashicorp.com/vagrant in conf.py (in a separate PR).

[ncoghlan]

#1912 removes the Vagrant link that is causing CI problems.

[webknjaz]

@ncoghlan that Update branch button usually has a drop-down. Whenever possible, choose the rebase option. Merge queues will already create merge commits, we shouldn't double their number if that can be avoided.

[webknjaz]

linkcheck crashes on 3 new broken links.

[ncoghlan]

For example, the link to https://packaging.python.org/en/latest/specifications/schemas/build-details-v1.0.schema.json in https://python-packaging-user-guide--1910.org.readthedocs.build/en/1910/specifications/build-details/v1.0/#build-details-v1-0 fails to resolve .

That's going to be a recurring bootstrapping problem: if the schema metadata links to their own canonical location from the $id field, the build that adds any given schema is going to fail (since it won't be present on the live site yet).

Can we instruct the link checker to resolve absolute https://packaging.python.org/en/latest/* links relative to the docs build anchor URL? (we don't want to make the $id fields themselves relative)