test(v2/runtime): fix vitest mock API usage in events tests (#5579)

* test(v2/runtime): fix vitest mock API usage in events tests

Three tests in desktop/events.test.js read mock invocations via
window.WailsInvoke.calls, which is the pre-1.0 vitest/jest spy shape;
modern vitest exposes them at .mock.calls, so the property was
undefined and the tests failed on every run ('should emit an event'
and both EventsOff/EventsOffAll cases). The suite has been red on
master independent of any product change.

Use .mock.calls. All 11 tests now pass; no product code touched.

* chore: remove UNRELEASED_CHANGELOG.md to avoid merge conflicts

Author: leaanthony

v2/internal/frontend/runtime/desktop/events.test.js

@@ -83,7 +83,7 @@ describe('EventsEmit', () => {
   it('should emit an event', () => {
     EventsEmit('a', 'one', 'two', 'three')
     expect(window.WailsInvoke).toBeCalledTimes(1);
-    const calledWith = window.WailsInvoke.calls[0][0];
+    const calledWith = window.WailsInvoke.mock.calls[0][0];
     expect(calledWith.slice(0, 2)).toBe('EE')
     expect(JSON.parse(calledWith.slice(2))).toStrictEqual({data: ["one", "two", "three"], name: "a"})
   })
@@ -113,7 +113,7 @@ describe('EventsOff', () => {
     expect(eventListeners['b']).toBeUndefined()
     expect(eventListeners['c']).not.toBeUndefined()
     expect(window.WailsInvoke).toBeCalledTimes(2);
-    expect(window.WailsInvoke.calls).toStrictEqual([['EXa'], ['EXb']]);
+    expect(window.WailsInvoke.mock.calls).toStrictEqual([['EXa'], ['EXb']]);
   })
 })
 
@@ -127,7 +127,7 @@ describe('EventsOffAll', () => {
     EventsOffAll()
     expect(eventListeners).toStrictEqual({})
     expect(window.WailsInvoke).toBeCalledTimes(3);
-    expect(window.WailsInvoke.calls).toStrictEqual([['EXa'], ['EXb'], ['EXc']]);
+    expect(window.WailsInvoke.mock.calls).toStrictEqual([['EXa'], ['EXb'], ['EXc']]);
   })
 })