⚰️ [#3489] Remove old HalClient

The HalClient variant of the ZDS Client is no longer used anywhere and
can be removed.

src/openforms/contrib/hal_client.py

@@ -1,6 +1,3 @@
-from zds_client.schema import get_operation_url
-from zgw_consumers.client import ZGWClient
-
 from api_client import APIClient
 
 HAL_CONTENT_TYPE = "application/hal+json"
@@ -19,23 +16,3 @@ def __init__(self, *args, **kwargs):
 
 class HALClient(HALMixin, APIClient):
     pass
-
-
-# deprecated
-class HalClient(ZGWClient):
-    def pre_request(self, method, url, kwargs):
-        """
-        Add authorization header to requests for APIs without jwt.
-        """
-
-        result = super().pre_request(method, url, kwargs)
-
-        headers = kwargs.get("headers", {})
-        headers["Accept"] = "application/hal+json"
-        headers["Content-Type"] = "application/hal+json"
-        return result
-
-    def get_operation_url(self, operation_id: str, **path_kwargs):
-        return get_operation_url(
-            self.schema, operation_id, base_url=self.api_root, **path_kwargs
-        )