[external-assets] asset checks dup check (#20361)

## Summary & Motivation

In the status quo, duplicate asset check keys are only caught during
asset job construction. This moves the duplicate check to the
definitions layer (where we catch dup asset keys).

## How I Tested These Changes

Updated existing unit test.

python_modules/dagster/dagster/_core/definitions/repository_definition/repository_data_builder.py

@@ -50,6 +50,7 @@
 from .valid_definitions import VALID_REPOSITORY_DATA_DICT_KEYS, RepositoryListDefinition
 
 if TYPE_CHECKING:
+    from dagster._core.definitions.asset_check_spec import AssetCheckKey
     from dagster._core.definitions.events import AssetKey
 
 
@@ -162,6 +163,7 @@ def build_caching_repository_data_from_list(
     sensors: Dict[str, SensorDefinition] = {}
     assets_defs: List[AssetsDefinition] = []
     asset_keys: Set[AssetKey] = set()
+    asset_check_keys: Set["AssetCheckKey"] = set()
     source_assets: List[SourceAsset] = []
     asset_checks_defs: List[AssetChecksDefinition] = []
     for definition in repository_definitions:
@@ -228,6 +230,10 @@ def build_caching_repository_data_from_list(
             source_assets.append(definition)
             asset_keys.add(definition.key)
         elif isinstance(definition, AssetChecksDefinition):
+            for key in definition.keys:
+                if key in asset_check_keys:
+                    raise DagsterInvalidDefinitionError(f"Duplicate asset check key: {key}")
+            asset_check_keys.update(definition.keys)
             asset_checks_defs.append(definition)
         else:
             check.failed(f"Unexpected repository entry {definition}")

python_modules/dagster/dagster/_core/definitions/repository_definition/valid_definitions.py

@@ -2,6 +2,7 @@
 
 from typing_extensions import TypeAlias
 
+from dagster._core.definitions.asset_checks import AssetChecksDefinition
 from dagster._core.definitions.graph_definition import GraphDefinition
 from dagster._core.definitions.job_definition import JobDefinition
 from dagster._core.definitions.schedule_definition import ScheduleDefinition
@@ -33,6 +34,7 @@
 
 RepositoryListDefinition: TypeAlias = Union[
     "AssetsDefinition",
+    AssetChecksDefinition,
     GraphDefinition,
     JobDefinition,
     ScheduleDefinition,

python_modules/dagster/dagster_tests/definitions_tests/decorators_tests/test_asset_check_decorator.py

@@ -380,7 +380,7 @@ def check1(context: AssetExecutionContext): ...
 
     with pytest.raises(
         DagsterInvalidDefinitionError,
-        match='Detected conflicting node definitions with the same name "asset1_check1"',
+        match="Duplicate asset check key.+asset1.+check1",
     ):
         Definitions(asset_checks=[make_check(), make_check()])