Fixes unit tests and token cleanup (#48005)

The unit tests in 2.8 were broken. this fixes them and adds a token
cleanup to the bigip_tunnel module

lib/ansible/modules/network/f5/bigip_tunnel.py

@@ -603,8 +603,10 @@ def main():
         client = F5RestClient(**module.params)
         mm = ModuleManager(module=module, client=client)
         results = mm.exec_module()
+        cleanup_tokens(client)
         exit_json(module, results, client)
     except F5ModuleError as ex:
+        cleanup_tokens(client)
         fail_json(module, ex, client)