fix: update schema registry cache after deleting subject (#1825)

Signed-off-by: 0xn4utilus <gyanendrabanjare8@gmail.com>

src/confluent_kafka/schema_registry/schema_registry_client.py

@@ -215,6 +215,26 @@ def set(self, schema_id, schema, subject_name=None):
             if subject_name is not None:
                 self.subject_schemas[subject_name].add(schema)
 
+    def remove_by_subject(self, subject_name):
+        """
+        Remove a Schema from the cache.
+
+        Args:
+            subject_name (str): Subject name the schema is registered under.
+        """
+
+
+        with self.lock:
+            if subject_name in self.subject_schemas:
+                for schema in self.subject_schemas[subject_name]:
+                    schema_id = self.schema_index.get(schema, None)
+                    if schema_id is not None:
+                        self.schema_id_index.pop(schema_id, None)
+                    self.schema_index.pop(Schema, None)
+
+                del self.subject_schemas[subject_name]
+
+
     def get_schema(self, schema_id):
         """
         Get the schema instance associated with schema_id from the cache.
@@ -546,7 +566,9 @@ def delete_subject(self, subject_name, permanent=False):
         if permanent:
             self._rest_client.delete('subjects/{}?permanent=true'
                                      .format(_urlencode(subject_name)))
-
+
+        self._cache.remove_by_subject(subject_name)
+
         return list
 
     def get_latest_version(self, subject_name):