chore: drop unused func
diff --git a/atmosphere/operator/utils.py b/atmosphere/operator/utils.py
index 57cfecc..b4d48e9 100644
--- a/atmosphere/operator/utils.py
+++ b/atmosphere/operator/utils.py
@@ -23,11 +23,3 @@
     ref = reference.Reference.parse(ref.string())
 
     return ref
-
-
-def filter_annotations(annotations: dict) -> dict:
-    return {
-        key: value
-        for key, value in annotations.items()
-        if key != "kopf.zalando.org/last-handled-configuration"
-    }