fix: Invalidate weak ptrs before window Javascript object is destroyed (#14532)

* fix: Invalidate weak ptrs before window Javascript object is destroyed

* chore: add regression test for #14513

This test is similar to the original gist at https://gist.github.com/bpasero/a02a645e11f4946dcca1331d0299149d -- the key is to open multiple windows and add an `app.on('browser-window-focus') listener that accesses window.id.

* fix: last commit didn't test the right thing.

The test needs to run in the main process to reproduce the
conditions reported in #14513

spec/api-browser-window-spec.js

@@ -221,6 +221,11 @@ describe('BrowserWindow module', () => {
         contents.getProcessId()
       }, /Object has been destroyed/)
     })
+    it('should not crash when destroying windows with pending events', (done) => {
+      const responseEvent = 'destroy-test-completed'
+      ipcRenderer.on(responseEvent, () => done())
+      ipcRenderer.send('test-browserwindow-destroy', { responseEvent })
+    })
   })
 
   describe('BrowserWindow.loadURL(url)', () => {