refactor inventory Loaders for ansible-inventory

* remove support for loading from executable and static files
* instead use ansible-inventory with fallback to backport
* provide private file dir in task manager for cred injection
* durable management of tmp dirs for user scripts

* new 'scm' source choice for scm-type
* update SCM inventory docs to new reality

awx/main/tests/functional/commands/test_inventory_import.py

@@ -117,7 +117,7 @@ class TestInvalidOptionsFunctional:
 @mock.patch.object(inventory_import.Command, 'set_logging_level', mock_logging)
 class TestINIImports:
 
-    @mock.patch.object(inventory_import.BaseLoader, 'load', mock.MagicMock(return_value=TEST_MEM_OBJECTS))
+    @mock.patch.object(inventory_import.AnsibleInventoryLoader, 'load', mock.MagicMock(return_value=TEST_MEM_OBJECTS))
     def test_inventory_single_ini_import(self, inventory, capsys):
         cmd = inventory_import.Command()
         r = cmd.handle_noargs(

awx/main/tests/functional/models/test_inventory.py

@@ -12,7 +12,8 @@ class TestSCMUpdateFeatures:
         inv_src = InventorySource(
             scm_project=project,
             source_path='inventory_file',
-            inventory=inventory)
+            inventory=inventory,
+            source='scm')
         with mock.patch.object(inv_src.scm_project, 'update') as mck_update:
             inv_src.save()
             mck_update.assert_called_once_with()