Fix indentation for typing.Unpack docs (#92058)

https://docs.python.org/3.11/library/typing.html#typing.Unpack

Author: JelleZijlstra

Doc/library/typing.rst

@@ -1368,27 +1368,27 @@ These are not used in annotations. They are building blocks for creating generic
 
 .. data:: Unpack
 
-    A typing operator that conceptually marks an object as having been
-    unpacked. For example, using the unpack operator ``*`` on a
-    :class:`type variable tuple <TypeVarTuple>` is equivalent to using ``Unpack``
-    to mark the type variable tuple as having been unpacked::
-
-        Ts = TypeVarTuple('Ts')
-        tup: tuple[*Ts]
-        # Effectively does:
-        tup: tuple[Unpack[Ts]]
-
-    In fact, ``Unpack`` can be used interchangeably with ``*`` in the context
-    of types. You might see ``Unpack`` being used explicitly in older versions
-    of Python, where ``*`` couldn't be used in certain places::
-
-        # In older versions of Python, TypeVarTuple and Unpack
-        # are located in the `typing_extensions` backports package.
-        from typing_extensions import TypeVarTuple, Unpack
-
-        Ts = TypeVarTuple('Ts')
-        tup: tuple[*Ts]         # Syntax error on Python <= 3.10!
-        tup: tuple[Unpack[Ts]]  # Semantically equivalent, and backwards-compatible
+   A typing operator that conceptually marks an object as having been
+   unpacked. For example, using the unpack operator ``*`` on a
+   :class:`type variable tuple <TypeVarTuple>` is equivalent to using ``Unpack``
+   to mark the type variable tuple as having been unpacked::
+
+      Ts = TypeVarTuple('Ts')
+      tup: tuple[*Ts]
+      # Effectively does:
+      tup: tuple[Unpack[Ts]]
+
+   In fact, ``Unpack`` can be used interchangeably with ``*`` in the context
+   of types. You might see ``Unpack`` being used explicitly in older versions
+   of Python, where ``*`` couldn't be used in certain places::
+
+      # In older versions of Python, TypeVarTuple and Unpack
+      # are located in the `typing_extensions` backports package.
+      from typing_extensions import TypeVarTuple, Unpack
+
+      Ts = TypeVarTuple('Ts')
+      tup: tuple[*Ts]         # Syntax error on Python <= 3.10!
+      tup: tuple[Unpack[Ts]]  # Semantically equivalent, and backwards-compatible
 
    .. versionadded:: 3.11