chore: fix security (non-)issue with poetry.lock in test (#25973)

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Author: RomainMuller

packages/@aws-cdk/aws-lambda-python-alpha/test/lambda-handler-poetry/poetry.lock

@@ -5,8 +5,8 @@ description = ""
 authors = ["Your Name <[email protected]>"]
 
 [tool.poetry.dependencies]
-python = "^3.6"
-requests = "2.26.0"
+python = "^3.7"
+requests = "^2.31.0"
 
 [tool.poetry.dev-dependencies]