Add nightly CI testing on Azure (AKS)

[MxNxPx]

Related to #213

Currently we do nightly testing on EKS. In order to expand our testing posture we should also test on AKS in Azure. The EKS testing is contained in these locations:

• Workflow: https://github.com/defenseunicorns/uds-core/blob/main/.github/workflows/nightly-testing.yaml
• Nightly bundle: https://github.com/defenseunicorns/uds-core/tree/main/.github/bundles
• Test infra: https://github.com/defenseunicorns/uds-core/tree/main/.github/test-infra/buckets-iac
• IAC task file: https://github.com/defenseunicorns/uds-core/blob/main/tasks/iac.yaml

Definition of done: Nightly test added to spin up AKS and deploy core (all flavors, matrixed) on it. There are multiple pre-reqs for this work including...

• Setup an Azure (Govcloud?) subscription for CI and plumb it up to GitHub
• Reuse and/or template out an AKS OpenTofu (using the internally built example) and tweak for fully automated create/destroy