Fix ios and iosxr terminal prompt regex (#39063)

Fixes #38732

Make matching leading newline for cli prompt
optional as there are cases when returned repsonse
for ios/iosx remote host doesn't have newline before
cli prompt.

lib/ansible/plugins/terminal/ios.py

@@ -30,7 +30,7 @@ from ansible.plugins.terminal import TerminalBase
 class TerminalModule(TerminalBase):
 
     terminal_stdout_re = [
-        re.compile(br"[\r\n][\w\+\-\.:\/\[\]]+(?:\([^\)]+\)){0,3}(?:[>#]) ?$")
+        re.compile(br"[\r\n]?[\w\+\-\.:\/\[\]]+(?:\([^\)]+\)){0,3}(?:[>#]) ?$")
     ]
 
     terminal_stderr_re = [

lib/ansible/plugins/terminal/iosxr.py

@@ -29,7 +29,7 @@ from ansible.errors import AnsibleConnectionFailure
 class TerminalModule(TerminalBase):
 
     terminal_stdout_re = [
-        re.compile(br"[\r\n][\w+\-\.:\/\[\]]+(?:\([^\)]+\)){,3}(?:>|#) ?$"),
+        re.compile(br"[\r\n]?[\w+\-\.:\/\[\]]+(?:\([^\)]+\)){,3}(?:>|#) ?$"),
         re.compile(br']]>]]>[\r\n]?')
     ]