Fix style fails for newer ruff.

Author: pp-mo

lib/iris/tests/__init__.py

@@ -447,9 +447,9 @@ def assertCML(self, cubes, reference_filename=None, checksum=True):
     def assertTextFile(self, source_filename, reference_filename, desc="text file"):
         """Check if two text files are the same, printing any diffs."""
         with open(source_filename) as source_file:
-            source_text = source_file.readlines()
+            source_text = list(source_file)  # a list of line strings
         with open(reference_filename) as reference_file:
-            reference_text = reference_file.readlines()
+            reference_text = list(reference_file)  # a list of line strings
         if reference_text != source_text:
             diff = "".join(
                 difflib.unified_diff(
@@ -548,9 +548,7 @@ def assertRepr(self, obj, reference_filename):
     def _check_same(self, item, reference_path, type_comparison_name="CML"):
         if self._check_reference_file(reference_path):
             with open(reference_path, "rb") as reference_fh:
-                reference = "".join(
-                    part.decode("utf-8") for part in reference_fh.readlines()
-                )
+                reference = "".join(part.decode("utf-8") for part in reference_fh)
             self._assert_str_same(reference, item, reference_path, type_comparison_name)
         else:
             self._ensure_folder(reference_path)

lib/iris/tests/integration/test_netcdf__loadsaveattrs.py

@@ -1022,7 +1022,7 @@ def test_16_localstyle(self, local_attr, origin_style, do_split):
         expected_result = [expect_global, expect_var]
         if do_split and origin_style == "input_global":
             # The result is simply the "other way around"
-            expected_result = expected_result[::-1]
+            expected_result.reverse()
         self.check_roundtrip_results(expected_result)
 
     @pytest.mark.parametrize("testcase", _MATRIX_TESTCASES[:max_param_attrs])