Pin charms to right versions in integration test files for versioned branches

Context

All the CKF charms repositories have a section in their integration tests that pins the channels of the charms required for the test to execute. For example, dex-auth:

OIDC_GATEKEEPER = "oidc-gatekeeper"
OIDC_GATEKEEPER_CHANNEL = "latest/edge"
OIDC_GATEKEEPER_CONFIG = {
    "client-name": "Ambassador Auth OIDC",
    "client-secret": "oidc-client-secret",
}

ISTIO_OPERATORS_CHANNEL = "latest/edge"
ISTIO_PILOT = "istio-pilot"
ISTIO_PILOT_TRUST = True
ISTIO_PILOT_CONFIG = {"default-gateway": "kubeflow-gateway"}
ISTIO_GATEWAY = "istio-gateway"
ISTIO_GATEWAY_APP_NAME = "istio-ingressgateway"
ISTIO_GATEWAY_TRUST = True
ISTIO_GATEWAY_CONFIG = {"kind": "ingress"}

KUBEFLOW_PROFILES = "kubeflow-profiles"
KUBEFLOW_PROFILES_CHANNEL = "latest/edge"
KUBEFLOW_PROFILES_TRUST = True

KUBEFLOW_DASHBOARD = "kubeflow-dashboard"
KUBEFLOW_DASHBOARD_CHANNEL = "latest/edge"
KUBEFLOW_DASHBOARD_TRUST = True

It has been done like this because the integration tests for the versioned charms (the ones running in track/version GH branches) may be different from the ones running on latest/edge (from the main GH branch), for example when there is a relation in main, but not in the versioned branch.

These versions have to be updated every time the charm gets a new versioned GH branch, for example, when there is a new release of CKF.

The process is manual at the moment and is a chore for the team. This is a proposal to automate that process whenever a branch for the new version is cut.

What needs to get done

Decide how this automation is going to be done
Implement the automation

Definition of Done

Integration tests run with the right version depending of the branch they are in.

canonical / bundle-kubeflow