stop using deprecated ElementTree methods "getchildren()" and "getiterator()"

Both methods were removed in Python 3.9 as mentioned in the release notes:

> Methods getchildren() and getiterator() of classes ElementTree and Element in
> the ElementTree module have been removed. They were deprecated in Python 3.2.
> Use iter(x) or list(x) instead of x.getchildren() and x.iter() or
> list(x.iter()) instead of x.getiterator().

Author: FelixSchwarz

scripts/import_cldr.py

@@ -598,7 +598,7 @@ def parse_calendar_months(data, calendar):
         for width in ctxt.findall('monthWidth'):
             width_type = width.attrib['type']
             widths = ctxts.setdefault(width_type, {})
-            for elem in width.getiterator():
+            for elem in width.iter():
                 if elem.tag == 'month':
                     _import_type_text(widths, elem, int(elem.attrib['type']))
                 elif elem.tag == 'alias':
@@ -616,7 +616,7 @@ def parse_calendar_days(data, calendar):
         for width in ctxt.findall('dayWidth'):
             width_type = width.attrib['type']
             widths = ctxts.setdefault(width_type, {})
-            for elem in width.getiterator():
+            for elem in width.iter():
                 if elem.tag == 'day':
                     _import_type_text(widths, elem, weekdays[elem.attrib['type']])
                 elif elem.tag == 'alias':
@@ -634,7 +634,7 @@ def parse_calendar_quarters(data, calendar):
         for width in ctxt.findall('quarterWidth'):
             width_type = width.attrib['type']
             widths = ctxts.setdefault(width_type, {})
-            for elem in width.getiterator():
+            for elem in width.iter():
                 if elem.tag == 'quarter':
                     _import_type_text(widths, elem, int(elem.attrib['type']))
                 elif elem.tag == 'alias':
@@ -649,7 +649,7 @@ def parse_calendar_eras(data, calendar):
     for width in calendar.findall('eras/*'):
         width_type = NAME_MAP[width.tag]
         widths = eras.setdefault(width_type, {})
-        for elem in width.getiterator():
+        for elem in width.iter():
             if elem.tag == 'era':
                 _import_type_text(widths, elem, type=int(elem.attrib.get('type')))
             elif elem.tag == 'alias':
@@ -676,7 +676,7 @@ def parse_calendar_periods(data, calendar):
 def parse_calendar_date_formats(data, calendar):
     date_formats = data.setdefault('date_formats', {})
     for format in calendar.findall('dateFormats'):
-        for elem in format.getiterator():
+        for elem in format.iter():
             if elem.tag == 'dateFormatLength':
                 type = elem.attrib.get('type')
                 if _should_skip_elem(elem, type, date_formats):
@@ -696,7 +696,7 @@ def parse_calendar_date_formats(data, calendar):
 def parse_calendar_time_formats(data, calendar):
     time_formats = data.setdefault('time_formats', {})
     for format in calendar.findall('timeFormats'):
-        for elem in format.getiterator():
+        for elem in format.iter():
             if elem.tag == 'timeFormatLength':
                 type = elem.attrib.get('type')
                 if _should_skip_elem(elem, type, time_formats):
@@ -717,7 +717,7 @@ def parse_calendar_datetime_skeletons(data, calendar):
     datetime_formats = data.setdefault('datetime_formats', {})
     datetime_skeletons = data.setdefault('datetime_skeletons', {})
     for format in calendar.findall('dateTimeFormats'):
-        for elem in format.getiterator():
+        for elem in format.iter():
             if elem.tag == 'dateTimeFormatLength':
                 type = elem.attrib.get('type')
                 if _should_skip_elem(elem, type, datetime_formats):
@@ -880,7 +880,7 @@ def parse_interval_formats(data, tree):
             interval_formats[None] = elem.text
         elif elem.tag == "intervalFormatItem":
             skel_data = interval_formats.setdefault(elem.attrib["id"], {})
-            for item_sub in elem.getchildren():
+            for item_sub in elem:
                 if item_sub.tag == "greatestDifference":
                     skel_data[item_sub.attrib["id"]] = split_interval_pattern(item_sub.text)
                 else:
@@ -903,7 +903,7 @@ def parse_currency_formats(data, tree):
                     type = '%s:%s' % (type, curr_length_type)
                 if _should_skip_elem(elem, type, currency_formats):
                     continue
-                for child in elem.getiterator():
+                for child in elem.iter():
                     if child.tag == 'alias':
                         currency_formats[type] = Alias(
                             _translate_alias(['currency_formats', elem.attrib['type']],