tests: Speed up transport config tests by avoiding interpreter discovery

Reduced execution time of tests/ansible/integration/transport_config/all.yml
from 11 minutes to 49 seconds.

tests/ansible/hosts/transport_config.hosts

@@ -1,55 +1,76 @@
 # integration/transport_config
 # Hosts with twiddled configs that need to be checked somehow.
 
+[transport_config:children]
+transport_config_undiscover
+tc_python_path
 
-# tansport()
+[transport_config_undiscover:children]
+tc_become
+tc_become_method
+tc_become_pass
+tc_become_user
+tc_password
+tc_port
+tc_remote_addr
+tc_remote_user
+tc_transport
+
+[transport_config_undiscover:vars]
+# If python interpreter path is unset, Ansible tries to connect & discover it.
+# That causes approx 10 seconds timeout per task - there's no host to connect to.
+# This optimisation should not be relied in any test.
+# Note: tc-python-path-* are intentionally not included.
+ansible_python_interpreter = python3000  # Not expected to exist
+
+[tc_transport]
 tc-transport-unset
 tc-transport-local ansible_connection=local
 tc-transport-smart ansible_connection=smart
 
-# python_path()
+[tc_python_path]
 tc-python-path-unset
 tc-python-path-hostvar  ansible_python_interpreter=/hostvar/path/to/python
 tc-python-path-local-unset ansible_connection=local
 tc-python-path-local-explicit ansible_connection=local ansible_python_interpreter=/a/b/c
 
-# remote_addr()
+[tc_remote_addr]
 tc-remote-addr-unset  # defaults to inventory_hostname
 tc-remote-addr-explicit-ssh ansible_ssh_host=ansi.ssh.host
 tc-remote-addr-explicit-host ansible_host=ansi.host
 tc-remote-addr-explicit-both ansible_ssh_host=a.b.c ansible_host=b.c.d
 
-# password()
+[tc_password]
 tc-password-unset
 tc-password-explicit-ssh  ansible_ssh_pass=ansi-ssh-pass
 tc-password-explicit-pass ansible_password=ansi-pass
 tc-password-explicit-both ansible_password=a.b.c ansible_ssh_pass=c.b.a
 
-# remote_user()
+[tc_remote_user]
 tc-remote-user-unset  # defaults to C.DEFAULT_REMOTE_USER
 tc-remote-user-explicit-ssh  ansible_ssh_user=ansi-ssh-user
 tc-remote-user-explicit-user ansible_user=ansi-user
 tc-remote-user-explicit-both ansible_user=a.b.c ansible_ssh_user=c.b.a
 
-# become()
+[tc_become]
 tc-become-unset
 tc-become-set
 
-# become_method()
+[tc_become_method]
 tc-become-method-unset
 tc-become-method-su ansible_become_method=su
 
-# become_user()
+[tc_become_user]
 tc-become-user-unset
 tc-become-user-set ansible_become_user=ansi-become-user
 
-# become_pass()
+[tc_become_pass]
 tc-become-pass-unset
 tc-become-pass-password ansible_become_password=apassword
 tc-become-pass-pass ansible_become_pass=apass
 tc-become-pass-both ansible_become_pass=bpass ansible_become_password=bpassword
 
-# port()
+[tc_port]
 tc-port-unset
 tc-port-explicit-port ansible_port=1234
 tc-port-explicit-ssh ansible_ssh_port=4321