- test_var_view.py, var_view.py: ruff compliance- prefer double quote…

…s instead of single quotes

pudb/test/test_var_view.py

@@ -520,7 +520,7 @@ def mocked_file_write(*args):
             for expr in expressions[:i + 1]:
                 expected_file_log.append((f"{str(expr)}\n", ))
 
-        with patch('builtins.open', mocked_open):
+        with patch("builtins.open", mocked_open):
             Watches.add(we_a)
             Watches.add(we_b)
             Watches.add(we_c)

pudb/var_view.py

@@ -846,10 +846,10 @@ def save(cls):
             return
 
         try:
-            with open(get_watches_file_name(), 'w+') as histfile:
+            with open(get_watches_file_name(), "w+") as histfile:
                 for watch in cls.all():
                     if watch:
-                        histfile.write(watch.expression + '\n')
+                        histfile.write(watch.expression + "\n")
 
         except Exception as save_exc:
             settings_log.exception("Failed to save watches", save_exc)
@@ -864,7 +864,7 @@ def load(cls):
         watch_fn = get_watches_file_name()
         if os.path.exists(watch_fn):
             try:
-                with open(watch_fn, 'r') as histfile:
+                with open(watch_fn, "r") as histfile:
                     cls._expressions = set()
                     for line in histfile.readlines():
                         cls._expressions.add(WatchExpression(line.strip()))