Is your feature request related to a problem? Please describe.
I'm working a bit of an edge case, pun intended, with azure custom cloud endpoints where I need to configure the entra endpoints similar to setting AzureGovernment, or AzureChina on the old sdk, but with custom values for azure stack edge. The newer azure-sdk-for-go supports custom entra configurations, but the archived go-autorest library this package is still using for the key vault client is limited to the 4 named environments.

Describe the solution you'd like
Update key vault client to use the newer sdk and expose the option for providing custom entra endpoints.

Describe alternatives you've considered
I've looked at SOPS, CSI driver, etc. The only tools that meet my architectural requirements are still using go-autorest or they don't support any configuration other than azure public cloud.

Additional context
I was concerned at first reading #5084, but I'm glad to see the showing of support. I can't provide much ongoing help, but I can take a crack at a PR for this issue if that is fine by the maintainers.