Deps: require translate-toolkit 3.1.0

This gets latest fixes in, including wxiki formats, JSON round trip
and dtd improvements.

requirements.txt

@@ -33,7 +33,7 @@ setuptools>=36.0.1
 siphashc>=1.2,<3.0
 social-auth-app-django==4.0.0
 social-auth-core==3.3.3
-translate-toolkit>=3.0.0,<3.2.0
+translate-toolkit>=3.1.0,<3.2.0
 translation-finder==2.2
 user-agents>=2.0,<2.3
 weblate-schemas==0.4

weblate/formats/tests/test_formats.py

@@ -23,7 +23,6 @@
 from io import BytesIO
 from unittest import SkipTest, TestCase
 
-import translate.__version__
 from django.utils.encoding import force_str
 from lxml import etree
 from translate.storage.po import pofile
@@ -470,11 +469,6 @@ class WebExtesionJSONFormatTest(JSONFormatTest):
     NEW_UNIT_MATCH = b'\n    "key": {\n        "message": "Source string"\n    }\n'
     EXPECTED_FLAGS = "placeholders:$URL$"
 
-    def test_new_unit(self):
-        if translate.__version__.ver <= (2, 2, 5):
-            raise SkipTest("Broken WebExtension support in translate-toolkit")
-        super().test_new_unit()
-
 
 class PhpFormatTest(AutoFormatTest):
     FORMAT = PhpFormat

weblate/formats/ttkit.py

@@ -816,16 +816,6 @@ def is_readonly(self):
 class BasePoFormat(TTKitFormat, BilingualUpdateMixin):
     loader = pofile
 
-    def is_valid(self):
-        result = super().is_valid()
-        if not result:
-            return False
-
-        # Avoid empty files with possibly syntax errors
-        # This can be removed once https://github.com/translate/translate/pull/3912
-        # is merged and relased in the Translate Toolkit
-        return bool(self.store.units)
-
     def get_plural(self, language):
         """Return matching plural object."""
         from weblate.lang.models import Plural
@@ -1331,13 +1321,7 @@ def extension():
     @property
     def all_store_units(self):
         """Wrapper for all store unit filtering out null."""
-        # The getattr is needed for translate-toolkit 3.0 and 3.1,
-        # once support for 3.0 is dropped, isblank can be used
-        return (
-            unit
-            for unit in self.store.units
-            if not getattr(unit, "isnull", unit.isblank)()
-        )
+        return (unit for unit in self.store.units if not unit.isblank())
 
 
 class SubtitleUnit(MonolingualIDUnit):