Enable TapRegion to detect all mouse button click (#136799)

With this PR, TapRegion would be able to detect any kind of mouse button
events. Earlier, TapRegion used to detect only left mouse button event.

Fixes #136706

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packages/flutter/lib/src/widgets/tap_region.dart

@@ -234,7 +234,7 @@ class RenderTapRegionSurface extends RenderProxyBoxWithHitTestBehavior implement
       return true;
     }(), 'A RenderTapRegion was registered when it was disabled.');
 
-    if (event is! PointerDownEvent || event.buttons != kPrimaryButton) {
+    if (event is! PointerDownEvent) {
       return;
     }