Give this artifact's bridge its own config and model subclasses (FastPLMs#50)

Artifacts share one FastPLMs runtime per process. Re-exported shared classes let one artifact's model class answer for another with the same config class, for example ESMFold2-300 built as ESMFold2Model after ESMFold2-Fast loaded. Only modeling_fastplms.py changes; the runtime bundle and weights are untouched. https://github.com/Synthyra/FastPLMs/issues/50

modeling_fastplms.py

@@ -180,14 +180,32 @@ def _install_runtime():
     return package
 
 _install_runtime()
-_module_182 = _import_without_bytecode("fastplms.models.esmfold2.configuration_esmfold2")
-ESMFold2Config = _module_182.ESMFold2Config
-ESMFold2Config.__module__ = __name__
-_module_185 = _import_without_bytecode("fastplms.models.esmfold2.modeling_esmfold2_classification")
-ESMFold2ExperimentalForSequenceClassification = _module_185.ESMFold2ExperimentalForSequenceClassification
-ESMFold2ExperimentalForSequenceClassification.__module__ = __name__
-ESMFold2ExperimentalForTokenClassification = _module_185.ESMFold2ExperimentalForTokenClassification
-ESMFold2ExperimentalForTokenClassification.__module__ = __name__
-_module_190 = _import_without_bytecode("fastplms.models.esmfold2.modeling_esmfold2_experimental")
-ESMFold2ExperimentalModel = _module_190.ESMFold2ExperimentalModel
-ESMFold2ExperimentalModel.__module__ = __name__
+
+def _artifact_class(base, config_class=None):
+    """Subclass a shared runtime class so this artifact registers its own classes.
+
+    The base constructor is kept explicitly because Transformers turns every config
+    subclass into a dataclass, which would otherwise generate a new constructor.
+    """
+    namespace = {
+        "__module__": __name__,
+        "__qualname__": base.__name__,
+        "__doc__": base.__doc__,
+        "__init__": base.__init__,
+    }
+    base_config_class = getattr(base, "config_class", None)
+    if (
+        config_class is not None
+        and isinstance(base_config_class, type)
+        and issubclass(config_class, base_config_class)
+    ):
+        namespace["config_class"] = config_class
+    return type(base.__name__, (base,), namespace)
+
+_module_204 = _import_without_bytecode("fastplms.models.esmfold2.configuration_esmfold2")
+_module_205 = _import_without_bytecode("fastplms.models.esmfold2.modeling_esmfold2_classification")
+_module_206 = _import_without_bytecode("fastplms.models.esmfold2.modeling_esmfold2_experimental")
+ESMFold2Config = _artifact_class(_module_204.ESMFold2Config)
+ESMFold2ExperimentalForSequenceClassification = _artifact_class(_module_205.ESMFold2ExperimentalForSequenceClassification, config_class=ESMFold2Config)
+ESMFold2ExperimentalForTokenClassification = _artifact_class(_module_205.ESMFold2ExperimentalForTokenClassification, config_class=ESMFold2Config)
+ESMFold2ExperimentalModel = _artifact_class(_module_206.ESMFold2ExperimentalModel, config_class=ESMFold2Config)