feat: warn on deprecated QuantinuumConfig usage

.cz.toml

@@ -3,7 +3,10 @@ name = "cz_customize"
 tag_format = "v$version"
 version = "7.3.0"
 version_scheme = "semver"
-version_files = ["pyproject.toml"]
+version_files = [
+    "pyproject.toml:version",
+    "uv.lock:version"
+]
 update_changelog_on_bump = true
 template = "templates/CHANGELOG.md.j2"
 

quantinuum_schemas/models/backend_config.py

@@ -8,6 +8,7 @@
 # pylint: disable=too-many-lines,no-member
 import abc
 from typing import Any, Dict, Literal, Optional, Type, TypeVar, Union
+import warnings
 
 from pydantic import ConfigDict, PositiveInt, field_validator, model_validator
 from pydantic.fields import Field
@@ -245,6 +246,27 @@ class QuantinuumConfig(BaseBackendConfig):
     max_cost: Optional[int] = None
     error_params: Optional[UserErrorParams] = None
 
+    @model_validator(mode="after")
+    def show_deprecation_warnings(self) -> Self:
+        """Warn about deprecated usage."""
+
+        if self.user_group is not None:
+            warnings.warn(
+                "'QuantinuumConfig.user_group' is deprecated and will be "
+                "removed in a future release. Please specify user_group in the execute job"
+                "submission parameters instead.",
+                DeprecationWarning,
+            )
+
+        if self.device_name.startswith("Helios"):
+            warnings.warn(
+                "QuantinuumConfig is deprecated for submission to Helios systems and support "
+                "will be removed in a future release. Please use HeliosConfig instead.",
+                DeprecationWarning,
+            )
+
+        return self
+
 
 class IBMQConfig(BaseBackendConfig):
     """Runs circuits on IBM's quantum devices."""