Address a few pedantic lints
lints are separated into separate commits so they can be reviewed
individually.
I've not added enforcement for any of these lints, but that could be
added if desirable.
Closes https://github.com/astral-sh/uv/issues/1709
Closes https://github.com/astral-sh/uv/issues/1371
Tested with the reproduction provided in #1709 which gets past the HTTP
401.
Reuses the same copying logic we introduced in
https://github.com/astral-sh/uv/pull/1874 to ensure authentication is
attached to file URLs with a realm that matches that of the index. I had
to move the authentication logic into a new crate so it could be used in
`distribution-types`.
We will want to something more robust in the future, like track all
realms with authentication in a central store and perform lookups there.
That's what `pip` does and it allows consolidation of logic like netrc
lookups. That refactor feels significant though, and I'd like to get
this fixed ASAP so this is a minimal fix.
