Deprecate/Remove Azure Spatial Anchors from the Mixed Reality extension

**Related command**

`az spatial-anchors-account` command group, its sub groups, and commands are deprecated as the Azure Spatial Anchors service was retired on November 20, 2024: https://azure.microsoft.com/en-us/updates?id=azure-spatial-anchors-retirement

Link to group: https://learn.microsoft.com/en-us/cli/azure/spatial-anchors-account?view=azure-cli-latest

**Describe the solution you'd like**

Update the Mixed Reality extension to remove the Azure Spatial Anchor commands