interfaces: convert `repository.ipeerconnection` from zope `Attribute` attrs

This is the same transformation as b455dfddfed0 did for dirstate.  Since type
annotations are wrapped up in this transformation (the file syntax is such that
*some* type needs to be declared, even if `Any`), this can be done piecemeal.
See that commit for more background detail.

Initially, I imported `uimod` here, delayed to the type checking phase, like a
bunch of other modules are currently doing.   That caused a problem with pytype
no longer inferring types in some seemingly unrelated modules, which was also
mentioned in a1c0f19e7cb4.  None of the following applies to this commit,
because dropping the import and aliasing `Ui = Any` until we get a Protocol
class in place avoids this issue.  But for posterity, the exact problem was that
pytype 2023.11.21 on Python 3.10.11 stopped inferring the (currently undeclared)
`int` type of the following attributes in `mercurial.revlog`, switching them to
`Any`.

    - COMP_MODE_INLINE
    - REVIDX_DEFAULT_FLAGS
    - REVIDX_ELLIPSIS
    - REVIDX_EXTSTORED
    - REVIDX_FLAGS_ORDER
    - REVIDX_HASCOPIESINFO
    - REVIDX_ISCENSORED
    - REVIDX_RAWTEXT_CHANGING_FLAGS

That had cascading effects on `hgext.remotefilelog.shallowutil`,
`mercurial.metadata`, and `mercurial.pure.parsers`, mostly on return types it
was no longer able to infer.  These fields above are imported directly through a
couple of `mercurial.revlogutils` modules.  Unfortunately, explicitly typing
those original fields only preserved the type for `COMP_MODE_INLINE`.  The only
difference I see is this field is defined in `mercurial/revlogutils/__init__.py`,
and the rest are defined in `mercurial/revlogutils/constants.py`, but I don't
know the significance of that.  The `mercurial/revlogutils/*.pyi` files have the
correct type with or without the explicit typing when the import is present- it's
only the `revlog` module's imports that seem to be affected.  And since they are
direct imports, there's no way that I know of to assign a type, like there would
be if there was a field assignment.

There is an import cycle of sorts here when importing ui, that is likely the
problem:

    interfaces.repository -> ui -> utils.urlutil -> revlogutils.constants -> interfaces.repository

Running `ls -gGrt --time-style=full` on the associated *.pyi files that get
generated showed that `revlog.pyi` was created before the `revlogutils` files.
I tried moving the import of `utils.urlutil` in `mercurial.ui` into `ui.paths()`
instead of a top level import, and that didn't help.  It could be argued that
`ui.pyi` would need the import anyway because `ui.paths()` returns an instance
of `utils.urlutil.paths`, but pytype is currently typing that as `Any`, because
it gets confused by the `@util.propertycache` decorator (replacing that with
`Any`), and it dropped the import of `utils.urlutil` as expected with that
change.

I'm a little skeptical that cycle is a problem though, because
`interfaces.repository` also started importing `utils.urlutil` here, which means
there's this cycle that's not a problem:

    interfaces.repository -> utils.urlutil -> revlogutils.constants -> interfaces.repository

PyCharm is also able to sniff out the types in `mercurial.revlog` with the
import, so I'm not sure if this is a bug/limitation in pytype, or what.

mercurial/interfaces/repository.py

@@ -8,7 +8,10
 
 from __future__ import annotations
 
+import typing
+
 from typing import (
+    Any,
     Protocol,
 )
 
@@ -16,6 +19,17 from ..i18n import _
 from .. import error
 from . import util as interfaceutil
 
+if typing.TYPE_CHECKING:
+    # Almost all mercurial modules are only imported in the type checking phase
+    # to avoid circular imports
+    from ..utils import (
+        urlutil,
+    )
+
+    # TODO: create a Protocol class, since importing uimod here causes a cycle
+    #  that confuses pytype.
+    Ui = Any
+
 # Local repository feature string.
 
 # Revlogs are being used for file storage.
@@ -112,8 +126,11 class ipeerconnection(Protocol):
     outside of this module.
     """
 
-    ui = interfaceutil.Attribute("""ui.ui instance""")
-    path = interfaceutil.Attribute("""a urlutil.path instance or None""")
+    ui: Ui
+    """ui.ui instance"""
+
+    path: urlutil.path | None
+    """a urlutil.path instance or None"""
 
     def url(self):
         """Returns a URL string representing this peer.