Clean up env vars

[zsusswein]

The same environment variables have different names in the R code and the python deployment scripts. They should be updated to use the same names, ideally using the python SDK's names as canonical.

See here

cfa-epinow2-pipeline/R/azure.R

Lines 106 to 108 in e8dc4ac

	az_tenant_id <- fetch_credential_from_env_var("az_tenant_id")
	az_client_id <- fetch_credential_from_env_var("az_client_id")
	az_service_principal <- fetch_credential_from_env_var("az_service_principal")

and here

cfa-epinow2-pipeline/azure/job.py

Lines 73 to 75 in e8dc4ac

	batchmodels.EnvironmentSetting(name="az_tenant_id", value=os.environ["AZURE_TENANT_ID"]),
	batchmodels.EnvironmentSetting(name="az_client_id", value=os.environ["AZURE_CLIENT_ID"]),
	batchmodels.EnvironmentSetting(name="az_service_principal", value=os.environ["AZURE_CLIENT_SECRET"])