Tag type:ignore as also unused-ignore to satisfy packages mypy

The Test Galaxy packages CI job runs mypy on each package's src/
in isolation (~418 files), where some imports referenced by the
ignored arg/type errors aren't visible. mypy then flags the ignore
itself as unused. The combined [type-abstract,unused-ignore] form
keeps the broader 'make mypy' (2207 files) silent while letting the
packaged-mypy treat the ignore as benign.

Author: mvdbeek

lib/galaxy/app/__init__.py

@@ -420,8 +420,8 @@ def _init_tool_source_store(self) -> None:
         )
 
         self.tool_source_store: Optional[ToolSourceStore] = self._register_singleton(
-            ToolSourceStore,  # type: ignore[type-abstract]
-            build_tool_source_store(self.config, self.model.context),  # type: ignore[arg-type]
+            ToolSourceStore,  # type: ignore[type-abstract,unused-ignore]
+            build_tool_source_store(self.config, self.model.context),  # type: ignore[arg-type,unused-ignore]
         )
         stats = self.tool_source_store.get_stats()
         tool_count = stats.get("count", 0)