Fix set literal.

spatialprofilingtoolbox/ondemand/service_client.py

@@ -129,7 +129,7 @@ def get_squidpy_metrics(
         radius: float | None = None,
     ) -> SquidpyMetricsComputationResult:
         """Get spatial proximity statistics between phenotype clusters as calculated by Squidpy."""
-        if not len(signature) in [1, 2]:
+        if not len(signature) in {1, 2}:
             raise ValueError(f'Expected 1 or 2 signatures/phenotypes but got {len(signature)}.')
         separator = self._get_record_separator()
         groups = [feature_class, self._sanitize_token(study)]