Bug fixes and cleanup for ansible-test. (#45991)

* Remove unused imports.
* Clean up ConfigParser usage in ansible-test.
* Fix bare except statements in ansible-test.
* Miscellaneous cleanup from PyCharm inspections.
* Enable pylint no-self-use for ansible-test.
* Remove obsolete pylint ignores for Python 3.7.
* Fix shellcheck issuers under newer shellcheck.
* Use newer path for ansible-test.
* Fix issues in code-smell tests.

test/runner/lib/cloud/gcp.py

@@ -6,9 +6,7 @@ from __future__ import absolute_import, print_function
 import os
 
 from lib.util import (
-    ApplicationError,
     display,
-    is_shippable,
 )
 
 from lib.cloud import (
@@ -16,9 +14,6 @@ from lib.cloud import (
     CloudEnvironment,
 )
 
-from lib.core_ci import (
-    AnsibleCoreCI, )
-
 
 class GcpCloudProvider(CloudProvider):
     """GCP cloud provider plugin. Sets up cloud resources before delegation."""