CI/CD - Define `RASAX_HELM_CHART_VERSION` in Makefile

[ArjaanBuijk]

When deploying older Rasa Enterprise versions, it is needed to use a rasa-x-helm chart compatible with that version. At the moment, always the latest version of the helm chart is used.

To find a compatible helm chart, use these commands:

#.............NAME   URL
helm repo add rasa-x https://rasahq.github.io/rasa-x-helm
helm repo update

# .................NAME  /CHARTNAME
$ helm search repo rasa-x/rasa-x --versions
NAME            CHART VERSION   APP VERSION DESCRIPTION                                 
rasa-x/rasa-x   2.0.0           0.41.1      Rasa X Helm chart for Kubernetes / Openshift
rasa-x/rasa-x   1.16.0          0.40.1      Rasa X Helm chart for Kubernetes / Openshift
..
rasa-x/rasa-x   1.7.0           0.33.0      Rasa X Helm chart for Kubernetes / Openshift
rasa-x/rasa-x   1.6.13          0.30.1      Rasa X Helm chart for Kubernetes / Openshift
# NOTE: APP VERSION = Rasa X version

For example, when deploying Rasa X 0.32.2, one might want to use CHART VERSION 1.6.13.

---

The Makefile must be updated as follows (make sure to use tabs, not spaces!):

# Make sure to use a compatible rasa-x-helm chart:
RASAX_HELM_CHART_VERSION := 1.6.13

rasa-enterprise-install:
    @echo - RASAX_HELM_CHART_VERSION: $(RASAX_HELM_CHART_VERSION)
    @echo $(NEWLINE)
    @helm --namespace $(AWS_EKS_NAMESPACE) \
        ....
        --version $(RASAX_HELM_CHART_VERSION) \
        $(AWS_EKS_RELEASE_NAME) \
        rasa-x/rasa-x

[ArjaanBuijk]

Done!