[DBMON-5558] Fix deprecation warnings on isSet() (DataDog#20947)

* Fix deprecation warnings on isSet()

* Add changelog

Author: eric-weaver

datadog_checks_base/changelog.d/20947.fixed

@@ -0,0 +1 @@
+Fixes deprecation warnings on isSet() usage in DBMAsyncJob

datadog_checks_base/datadog_checks/base/utils/db/utils.py

@@ -334,7 +334,7 @@ def _job_loop(self):
         try:
             self._log.info("[%s] Starting job loop", self._job_tags_str)
             while True:
-                if self._cancel_event.isSet():
+                if self._cancel_event.is_set():
                     self._log.info("[%s] Job loop cancelled", self._job_tags_str)
                     self._check.count("dd.{}.async_job.cancel".format(self._dbms), 1, tags=self._job_tags, raw=True)
                     break
@@ -353,7 +353,7 @@ def _job_loop(self):
                 else:
                     self._run_job_rate_limited()
         except Exception as e:
-            if self._cancel_event.isSet():
+            if self._cancel_event.is_set():
                 # canceling can cause exceptions if the connection is closed the middle of the check run
                 # in this case we still want to report it as a cancellation instead of a crash
                 self._log.debug("[%s] Job loop error after cancel: %s", self._job_tags_str, e)
@@ -400,7 +400,7 @@ def _run_job_rate_limited(self):
         except:
             raise
         finally:
-            if not self._cancel_event.isSet():
+            if not self._cancel_event.is_set():
                 self._rate_limiter.update_last_time_and_sleep()
             else:
                 self._rate_limiter.update_last_time()