[3.11] gh-115652: Fix indentation in the documentation of multiprocessing.get_start_method (GH-115658) (GH-115660)

(cherry picked from commit d504968)

Co-authored-by: Daniel Haag <121057143+denialhaag@users.noreply.github.com>

Author: miss-islington

Doc/library/multiprocessing.rst

@@ -1065,13 +1065,13 @@ Miscellaneous
    or ``None``.  ``'fork'`` is the default on Unix, while ``'spawn'`` is
    the default on Windows and macOS.
 
-.. versionchanged:: 3.8
+   .. versionadded:: 3.4
 
-   On macOS, the *spawn* start method is now the default.  The *fork* start
-   method should be considered unsafe as it can lead to crashes of the
-   subprocess. See :issue:`33725`.
+   .. versionchanged:: 3.8
 
-   .. versionadded:: 3.4
+      On macOS, the *spawn* start method is now the default.  The *fork* start
+      method should be considered unsafe as it can lead to crashes of the
+      subprocess. See :issue:`33725`.
 
 .. function:: set_executable(executable)