[web] Unify line boundary expectations on web and non-web (#121006)

* [web] Temporarily disable a line boundary test

* [web] Unify line boundary expectations on web and non-web

packages/flutter/test/rendering/paragraph_test.dart

@@ -1059,15 +1059,8 @@ void main() {
         ),
       );
       selection = paragraph.selections[0];
-      expect(selection.start, 4); // how [are you]
-      if (isBrowser && !isCanvasKit) {
-        // TODO(mdebbar): Remove this "if" once this engine PR lands:
-        // https://github.com/flutter/engine/pull/39693
-
-        // expect(selection.end, 12);
-      } else {
-        expect(selection.end, 11);
-      }
+      // how [are you]
+      expect(selection, const TextRange(start: 4, end: 11));
 
       // Equivalent to sending shift + meta + arrow-left.
       registrar.selectables[0].dispatchSelectionEvent(
@@ -1078,16 +1071,8 @@ void main() {
         ),
       );
       selection = paragraph.selections[0];
-      if (isBrowser && !isCanvasKit) {
-        // TODO(mdebbar): Remove this "if" once this engine PR lands:
-        // https://github.com/flutter/engine/pull/39693
-
-        // how [are you\n]
-        // expect(selection, const TextRange(start: 4, end: 12));
-      } else {
-        // [how ]are you
-        expect(selection, const TextRange(start: 0, end: 4));
-      }
+      // [how ]are you
+      expect(selection, const TextRange(start: 0, end: 4));
     });
 
     test('can granularly extend selection - document', () async {