convert SwathRfiInfo to return an instance, remove the ipf check fr…

…om classmethod

Since the ET cant be parsed if the file doesnt exist, not clear how the check would fail

src/s1reader/s1_annotation.py

@@ -672,12 +672,6 @@ def from_et(cls,
         cls: SwathRfiInfo
             dataclass populated by this function
         '''
-
-        if ipf_version < RFI_INFO_AVAILABLE_FROM:
-            # RFI related processing is not in place
-            # return an empty dataclass
-            return None
-
         # Attempt to locate the RFI information from the input annotations
         header_lads = et_product.find('imageAnnotation/processingInformation')
         if header_lads is None:
@@ -690,22 +684,27 @@ def from_et(cls,
                              'in the RFI annotation')
 
         # Start to load RFI information
-        cls.rfi_mitigation_performed =\
+        rfi_mitigation_performed =\
             header_lads.find('rfiMitigationPerformed').text
-        cls.rfi_mitigation_domain =\
+        rfi_mitigation_domain =\
             header_lads.find('rfiMitigationDomain').text
 
         num_burst_rfi_report = len(header_rfi)
-        cls.rfi_burst_report_list = [None] * num_burst_rfi_report
-        cls.azimuth_time_list = [None] * num_burst_rfi_report
+        rfi_burst_report_list = [None] * num_burst_rfi_report
+        azimuth_time_list = [None] * num_burst_rfi_report
 
         for i_burst, elem_burst in enumerate(header_rfi):
-            cls.rfi_burst_report_list[i_burst] =\
+            rfi_burst_report_list[i_burst] =\
                 element_to_dict(elem_burst)['rfiBurstReport']
-            cls.azimuth_time_list[i_burst] =\
-                cls.rfi_burst_report_list[i_burst]['azimuthTime']
+            azimuth_time_list[i_burst] =\
+                rfi_burst_report_list[i_burst]['azimuthTime']
 
-        return cls
+        return cls(
+            rfi_mitigation_performed,
+            rfi_mitigation_domain,
+            rfi_burst_report_list,
+            azimuth_time_list,
+        )
 
 
     @classmethod

src/s1reader/s1_reader.py

@@ -576,9 +576,7 @@ def burst_from_xml(annotation_path: str, orbit_path: str, tiff_path: str,
                                             'annotation/rfi/rfi-')
             with open_method(rfi_annotation_path, 'r') as f_rads:
                 tree_rads = ET.parse(f_rads)
-                burst_rfi_info_swath = SwathRfiInfo.from_et(tree_rads,
-                                                            tree_lads,
-                                                            ipf_version)
+                burst_rfi_info_swath = SwathRfiInfo.from_et(tree_rads, tree_lads)
 
         else:
             burst_rfi_info_swath = None