Resolve some Sphinx doc build errors

Sphinx doesn't set `TYPE_CHECKING`, but does use the type annotations.
`Self` is unknown to Sphinx, so should be filtered out to prevent lots
of errors.

Author: rgommers

src/_array_api_conf.py

@@ -61,6 +61,7 @@
     ('py:class', '.*array'),
     ('py:class', '.*device'),
     ('py:class', '.*dtype'),
+    ('py:class', '.*Self'),
     ('py:class', '.*NestedSequence'),
     ('py:class', '.*SupportsBufferProtocol'),
     ('py:class', '.*PyCapsule'),

src/array_api_stubs/_draft/array_object.py

@@ -2,15 +2,14 @@
 
 from typing import TYPE_CHECKING, Protocol, TypeVar
 
-if TYPE_CHECKING:
-    from ._types import (
-        dtype as Dtype,
-        device as Device,
-        Any,
-        PyCapsule,
-        Enum,
-        ellipsis,
-    )
+from ._types import (
+    dtype as Dtype,
+    device as Device,
+    Any,
+    PyCapsule,
+    Enum,
+    ellipsis,
+)
 
 Self = TypeVar("Self", bound="Array")
 # NOTE: when working with py3.11+ this can be ``typing.Self``.