Switch async_extra_data test to inventory file.

test/integration/targets/async_extra_data/inventory

@@ -0,0 +1 @@
+localhost ansible_connection=ssh ansible_python_interpreter="{{ ansible_playbook_python }}"

test/integration/targets/async_extra_data/runme.sh

@@ -3,7 +3,7 @@
 set -eux
 
 # Verify that extra data before module JSON output during async call is ignored.
-ANSIBLE_DEBUG=0 LC_ALL=bogus ansible-playbook test_async.yml -i localhost, -e ansible_connection=ssh -v "$@"
+ANSIBLE_DEBUG=0 LC_ALL=bogus ansible-playbook test_async.yml -i inventory -v "$@"
 # Verify that the warning exists by examining debug output.
-ANSIBLE_DEBUG=1 LC_ALL=bogus ansible-playbook test_async.yml -i localhost, -e ansible_connection=ssh -v "$@" \
+ANSIBLE_DEBUG=1 LC_ALL=bogus ansible-playbook test_async.yml -i inventory -v "$@" \
     | grep 'bash: warning: setlocale: LC_ALL: cannot change locale (bogus)' > /dev/null