Update a sample app to flask 2.2.4

Author: bitterpanda63

sample-apps/flask-mongo/poetry.lock

@@ -4,7 +4,7 @@ version = "0.1.0"
 description = "Sample app Flask Mongo"
 requires-python = ">3.9.1,<4.0"
 dependencies = [
-    "flask (>=3.1.0,<4.0.0)",
+    "flask (==2.2.4)",
     "requests (>=2.32.3,<3.0.0)",
     "cryptography (>=44.0.0,<45.0.0)",
     "aikido_zen",