Deprecates all cases where `Link` could be sent as a prop. This was a
relic from the past, where we attempted to make our UI library
router-agnostic. This was a pipe dream and created more problems than it
solved, for example the logout button was missing this prop, causing it
to render an anchor tag and perform a hard navigation (caught in #9275).

Does so in a non-breaking way, where these props are now optional and
simply unused, as opposed to removing them outright.

Deprecates all cases where `Link` could be sent as a prop. This was a
relic from the past, where we attempted to make our UI library
router-agnostic. This was a pipe dream and created more problems than it
solved, for example the logout button was missing this prop, causing it
to render an anchor tag and perform a hard navigation (caught in #9275).

Does so in a non-breaking way, where these props are now optional and
simply unused, as opposed to removing them outright.

This PR resolves an issue where the `href` for the Logout button in the
admin panel included duplicate `basePath` values when `basePath` was set
in `next.config.js`.

The Logout button was recently updated to use `NextLink` (`next/link`),
which automatically applies the `basePath` from the Next.js
configuration. As a result, manually adding the `basePath` to the `href`
is no longer necessary.

Relevant PRs that modified this behavior originally: 
- #9275
- #11155

When visiting a collection's list view, the nav item corresponding to
that collection correctly appears in an active state, but is still
rendered as an anchor tag. This makes it possible to reload the current
page by simply clicking the link, which is a problem because this
performs an unnecessary server roundtrip. This is especially apparent
when search params exist in the current URL, as the href on the link
does not.

Unrelated: also cleans up leftover code that was missed in this PR:
#11155

payloadcms/payload#11155