Add phi check for section properties validation

To avoid a RuntimeError that a argument of type "float | None" cannot be assigned to parameter "phi" of type "float" in function fea.principal_coordinate" (line 318)

Author: jchkoch

src/sectionproperties/analysis/section.py

@@ -299,7 +299,7 @@ def calculate_geom(progress: Progress | None = None) -> None:
             i11 = self.section_props.i11_c
             i22 = self.section_props.i22_c
 
-            if ixx is None or iyy is None or ixy is None or i11 is None or i22 is None:
+            if ixx is None or iyy is None or ixy is None or i11 is None or i22 is None or phi is None:
                 msg = "Section properties failed to save."
                 raise RuntimeError(msg)