Show something useful from EvtSubscribe_push demo

CHANGES.txt

@@ -15,6 +15,7 @@ Coming in build 307, as yet unreleased
 --------------------------------------
 
 ### pywin32
+* The `EvtSubscribe_push` demo now actually demonstrates the callback action and the event context being filled. (#2281, @Avasam)
 * Fixed accidentally trying to raise a `str` instead of an `Exception` in (#2270, @Avasam)
   * `Pythonwin/pywin/debugger/debugger.py`
   * `Pythonwin/pywin/framework/dlgappcore.py`

win32/Demos/EvtSubscribe_push.py

@@ -1,4 +1,8 @@
 ## Demonstrates a "push" subscription with a callback function
+from __future__ import annotations
+
+from time import sleep
+
 import win32evtlog
 
 query_text = '*[System[Provider[@Name="Microsoft-Windows-Winlogon"]]]'
@@ -15,11 +19,14 @@ def c(reason, context, evt):
     return 0
 
 
-evttext = []
+evttext: list[str] = []
 s = win32evtlog.EvtSubscribe(
     "System",
     win32evtlog.EvtSubscribeStartAtOldestRecord,
     Query="*",
     Callback=c,
     Context=evttext,
 )
+
+sleep(0.001)
+print("\n".join(evttext))