Remove `typing.Self` workaround

Remove ``typing.Self`` workaround, now using :pep:`673` for most methods
that return ``Self``. Pull request courtesy Yurii Karabas.

Fixes: #9254
Closes: #9255
Pull-request: https://github.com/sqlalchemy/sqlalchemy/pull/9255
Pull-request-sha: 2947df8ada79f5c3afe9c838e65993302199c2f7

Change-Id: Ic32015ad52e95a61f3913d43ea436aa9402804df

1 files changed, 5 insertions, 9 deletions

diff --git a/lib/sqlalchemy/dialects/postgresql/dml.py b/lib/sqlalchemy/dialects/postgresql/dml.py
index 5e569869e..a1807d7b3 100644
--- a/lib/sqlalchemy/dialects/postgresql/dml.py
+++ b/lib/sqlalchemy/dialects/postgresql/dml.py
@@ -6,8 +6,6 @@
 # the MIT License: https://www.opensource.org/licenses/mit-license.php
 # mypy: ignore-errors
 
-import typing
-
 from . import ext
 from ... import util
 from ...sql import coercions
@@ -19,6 +17,7 @@ from ...sql.base import ColumnCollection
 from ...sql.dml import Insert as StandardInsert
 from ...sql.elements import ClauseElement
 from ...sql.expression import alias
+from ...util.typing import Self
 
 
 __all__ = ("Insert", "insert")
@@ -44,9 +43,6 @@ def insert(table):
     return Insert(table)
 
 
-SelfInsert = typing.TypeVar("SelfInsert", bound="Insert")
-
-
 class Insert(StandardInsert):
     """PostgreSQL-specific implementation of INSERT.
 
@@ -100,13 +96,13 @@ class Insert(StandardInsert):
     @_generative
     @_on_conflict_exclusive
     def on_conflict_do_update(
-        self: SelfInsert,
+        self,
         constraint=None,
         index_elements=None,
         index_where=None,
         set_=None,
         where=None,
-    ) -> SelfInsert:
+    ) -> Self:
         r"""
         Specifies a DO UPDATE SET action for ON CONFLICT clause.
 
@@ -168,11 +164,11 @@ class Insert(StandardInsert):
     @_generative
     @_on_conflict_exclusive
     def on_conflict_do_nothing(
-        self: SelfInsert,
+        self,
         constraint=None,
         index_elements=None,
         index_where=None,
-    ) -> SelfInsert:
+    ) -> Self:
         """
         Specifies a DO NOTHING action for ON CONFLICT clause.