use f-strings in module utils (#10901)

* use f-strings in module utils

* Apply suggestions from code review

Co-authored-by: Felix Fontein <felix@fontein.de>

* remove unused imports

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Co-authored-by: Felix Fontein <felix@fontein.de>

plugins/module_utils/lxd.py

@@ -78,7 +78,7 @@ class LXDClient(object):
     def do(self, method, url, body_json=None, ok_error_codes=None, timeout=None, wait_for_container=None):
         resp_json = self._send_request(method, url, body_json=body_json, ok_error_codes=ok_error_codes, timeout=timeout)
         if resp_json['type'] == 'async':
-            url = '{0}/wait'.format(resp_json['operation'])
+            url = f"{resp_json['operation']}/wait"
             resp_json = self._send_request('GET', url)
             if wait_for_container:
                 while resp_json['metadata']['status'] == 'Running':