add lint fix and add slack notifications (#815)

Author: ssh-esh

catalog-info.yaml

@@ -53,6 +53,9 @@ spec:
     spec:
       pipeline_file: .buildkite/pipeline.yml
       repository: elastic/eland
+      env:
+        ELASTIC_SLACK_NOTIFICATIONS_ENABLED: 'true'
+        SLACK_NOTIFICATIONS_CHANNEL: '#devtools-notify'
       teams:
         ml-core: {}
         devtools-team: {}

eland/operations.py

@@ -185,7 +185,7 @@ def _metric_agg_series(
         else:
             # If all results are float convert into float64
             if all(isinstance(i, float) for i in results.values()):
-                dtype: "DTypeLike" = np.float64
+                dtype: "DTypeLike | None" = np.float64
             # If all results are int convert into int64
             elif all(isinstance(i, int) for i in results.values()):
                 dtype = np.int64