[FIX] web_editor: remove broken and unnecessary test

The next test was identical to the removed one, with the exception that
it inserts a character at the end, which really is the behavior we want
to test. The removed test was broken because it expected the range on
the parent, which is anyway equivalent in this case. This is confirmed
by the fact that inserting a character at either ranges indeed inserts
the character where it is expected to do so.

addons/web_editor/static/tests/wysiwyg_keyboard_tests.js

@@ -3092,22 +3092,6 @@ var keyboardTestsBackspace = [{
             start: "p:contents()[0]->4",
         },
     },
-    {
-        name: "in complex-dom (empty-td (td before) -> 2x SHIFT-ENTER): 3x BACKSPACE",
-        content: '<table class="table table-bordered"><tbody><tr><td><p>dom not to edit</p></td><td><p><br><br><br></p></td></tr></tbody></table>',
-        steps: [{
-            start: 'p:eq(1)->3',
-            key: 'BACKSPACE',
-        }, {
-            key: 'BACKSPACE',
-        }, {
-            key: 'BACKSPACE',
-        }],
-        test: {
-            content: '<table class="table table-bordered"><tbody><tr><td><p>dom not to edit</p></td><td><p><br></p></td></tr></tbody></table>',
-            start: "p:eq(1):contents()[0]->0",
-        },
-    },
     {
         name: "in complex-dom (empty-td (td before) -> 2x SHIFT-ENTER): 3x BACKSPACE -> 'a'",
         content: '<table class="table table-bordered"><tbody><tr><td><p>dom not to edit</p></td><td><p><br><br><br></p></td></tr></tbody></table>',