chore(python): headers type

Author: Fluf22

templates/python/config.mustache

@@ -1,5 +1,5 @@
 from os import environ
-from typing import Optional
+from typing import Dict, Optional
 
 from algoliasearch.http.hosts import (
   CallType,
@@ -29,7 +29,7 @@ class {{#lambda.pascalcase}}{{client}}{{/lambda.pascalcase}}Config(BaseConfig):
         if api_key is None or not api_key:
              raise ValueError("`api_key` is missing.")
 
-        self.headers = {
+        self.headers: Dict[string, string] = {
              "x-algolia-application-id": app_id,
              "x-algolia-api-key": api_key,
              "user-agent": self._user_agent.get(),