[pre-commit][kuttl]Check for multiple TestAsserts

Add a new pre-commit check to avoid using more than one TestAssert in a
single kuttl assert file as that can lead to false positives as only the
last TestAssert is run by kuttl.

Fortunately there was no such issue in this repo.

.pre-commit-config.yaml

@@ -53,3 +53,11 @@ repos:
     - id: no-commit-to-branch
     - id: trailing-whitespace
       exclude: ^vendor
+
+- repo: https://github.com/openstack-k8s-operators/openstack-k8s-operators-ci
+  # NOTE(gibi): we cannot automatically track main here
+  # see https://pre-commit.com/#using-the-latest-version-for-a-repository
+  rev: e30d72fcbced0ab8a7b6d23be1dee129e2a7b849
+  hooks:
+    - id: kuttl-single-test-assert
+      args: ["tests/kuttl"]