deprecate scp_if_ssh (#75218)

* deprecate scp_if_ssh

Co-authored-by: Matt Martz <matt@sivel.net>

changelogs/fragments/deprecate_scp_if_ssh.yml

@@ -0,0 +1,2 @@
+deprecated_features:
+  - ssh connection plugin option scp_if_ssh in favor of ssh_transfer_method.

lib/ansible/plugins/connection/ssh.py

@@ -289,6 +289,10 @@ DOCUMENTATION = '''
             - name: ansible_ssh_transfer_method
               version_added: '2.12'
       scp_if_ssh:
+        deprecated:
+              why: In favor of the "ssh_transfer_method" option.
+              version: "2.17"
+              alternatives: ssh_transfer_method
         default: smart
         description:
           - "Preferred method to use when transfering files over SSH."