chore/Remove Pytest

We've got a security issue related to Pytest, but whilst we have a test
directory, it doesn't actually have any tests.  Therefore, rather than
keeping Pytest up to date we're going to remove it as we're not using it

Author: KPobeeNorris

infrastructure/energy-apps-cdk/poetry.lock

@@ -8,7 +8,6 @@ package-mode = false
 
 [tool.poetry.dependencies]
 python = ">=3.12, <3.13"
-pytest = "8.3.3"
 ca-cdk-constructs = "^0.17.1"
 aws-cdk-cli = "^2.1017.1"