Tests: Remove suite level apply_modifiers option for modifier tests

The `apply_modifiers` property of the `RunTest` class overrides
all of the test level `apply_modifier` properties. This prevents
modifiers from manually specifying when a modifier is applied and forces
the modifier to be applied immediately after it is added.

The vast majority of tests do not override the `apply_modifier`
property, the primary usecase for this property is to work in
combination with the `do_compare` property to allow examining the
corresponding .blend file to debug test failures.

This commit simplifies the settings by removing this parameter. It now
only disables applying the modifier if `do_compare` is set to False.

Pull Request: https://projects.blender.org/blender/blender/pulls/140893

tests/python/modifiers.py

@@ -342,12 +342,10 @@ def main():
     command = list(sys.argv)
     for i, cmd in enumerate(command):
         if cmd == "--run-all-tests":
-            modifiers_test.apply_modifiers = True
             modifiers_test.do_compare = True
             modifiers_test.run_all_tests()
             break
         elif cmd == "--run-test":
-            modifiers_test.apply_modifiers = False
             modifiers_test.do_compare = False
             name = command[i + 1]
             modifiers_test.run_test(name)