Remove redundant mandatory properties

RE mantidproject#38523

Author: cailafinn

Framework/PythonInterface/plugins/algorithms/WorkflowAlgorithms/SANS/SANSSave.py

@@ -314,18 +314,9 @@ def _validate_pol_props(self, errors):
         if not polarization_props:
             errors.update({"PolarizationProps": "PolarizationProps must be set to use SavePolarizedNXCanSAS."})
             return
-        mandatory_props = [
-            "InputSpinStates",
-            "PolarizerComponentName",
-            "AnalyzerComponentName",
-            "FlipperComponentNames",
-            "MagneticFieldStrengthLogName",
-            "MagneticFieldDirection",
-        ]
-        if not all(prop in polarization_props.keys() for prop in mandatory_props):
-            missing_props = set(mandatory_props) - set(polarization_props.keys())
+        if "InputSpinStates" not in polarization_props.keys():
             errors.update(
-                {"PolarizationProps": f"Missing property for SavePolarizedNXCanSAS. These properties are missing: {missing_props}"}
+                {"PolarizationProps": "Missing property for SavePolarizedNXCanSAS. These properties are missing: InputSpinStates."}
             )
 
     def _get_file_formats(self):

Testing/SystemTests/tests/framework/ISIS/SANS/WORKFLOWS/SANSSaveTest.py

@@ -254,28 +254,19 @@ def test_polarization_props_throws_when_any_mandatory_properties_unset(self):
 
         file_name = os.path.join(mantid.config.getString("defaultsave.directory"), "sample_sans_save_file")
         pol_props = {
-            "InputSpinStates": "0,1",
-            "PolarizerComponentName": "a",
-            "AnalyzerComponentName": "b",
-            "FlipperComponentNames": ["c", "d", "e"],
-            "MagneticFieldStrengthLogName": "f",
-            "MagneticFieldDirection": "g,h,i",
+            "InputSpinStatez": "0,1",
         }
-        for i in range(0, len(pol_props)):
-            one_removed = pol_props.copy()
-            one_removed.pop(list(one_removed.keys())[i])
-            with self.assertRaisesRegex(
-                RuntimeError,
-                f".*PolarizationProps: Missing property for SavePolarizedNXCanSAS. "
-                f"These properties are missing: {{'{list(pol_props.keys())[i]}'}}",
-            ):
-                # Act
-                SANSSave(
-                    InputWorkspace=workspace,
-                    Filename=file_name,
-                    PolarizedNXCanSAS=True,
-                    PolarizationProps=one_removed,
-                )
+        with self.assertRaisesRegex(
+            RuntimeError,
+            ".*PolarizationProps: Missing property for SavePolarizedNXCanSAS. These properties are missing: InputSpinStates",
+        ):
+            # Act
+            SANSSave(
+                InputWorkspace=workspace,
+                Filename=file_name,
+                PolarizedNXCanSAS=True,
+                PolarizationProps=pol_props,
+            )
 
     def test_polarizer_algorithm_executed(self):
         # Arrange