Convert polygonal aperture rotations to radians

Polygonal aperture rotations are specified in degrees, however
gerbonara wants radians. This is a fix for issue #12 :

https://gitlab.com/gerbolyze/gerbonara/-/issues/12

src/gerbonara/rs274x.py

@@ -878,6 +878,10 @@ class GerberParser:
             if match['shape'] in 'RO' and (math.isclose(modifiers[0], 0) or math.isclose(modifiers[1], 0)):
                 self.warn('Definition of zero-width and/or zero-height rectangle or obround aperture. This is invalid according to spec.' )
 
+            # Polygon aperture rotation is specified in degrees, but radians are easier to work with
+            if match['shape'] == 'P':
+                modifiers[2] = math.radians(modifiers[2])
+
             new_aperture = kls(*modifiers, unit=self.file_settings.unit, attrs=tuple(self.aperture_attrs.items()),
                     original_number=number)