Template non-functional due to Azure APIs being deprecated

[samlayton]

On Monday the 1st of July, Azure deprecated all API versions prior to 2021-08-01

This means any ARM template referencing older resources will fail. As most of the templates in this repo reference old API versions, they no longer function. Examples:

azure-functions-splunk/event-hubs-hec/deploy/azureDeploy.portal.json

Line 87 in 8f75ace

"path": "[concat(subscription().id, '/providers/Microsoft.EventHub/namespaces', '?api-version=2017-04-01')]"

azure-functions-splunk/event-hubs-hec/deploy/azureDeploy.json

Line 237 in 8f75ace

"apiVersion": "2019-06-01",

Please can you update the templates so that we can continue using them now the APIs have been deprecated?