DefaultAzureCredential prints libsecret errors in linux container from SharedTokenCacheCredential

[vxfield]

Related to: Azure/azure-sdk-for-python#19857

The custom _DefaultAzureCredential() that we use as a default credential for the Workspace has an issue with the SharedTokenCacheCredential in a linux docker container.
It dumps either pyobject or libsecret errors from the SharedTokenCacheCredential, which is confusing to users.

It also looks like DotNet Azure.Identity excludes SharedTokenCacheCredential by default. For consistency across SDKs, it would also be great if azure-sdk-for-python similarly excluded SharedTokenCacheCredential from DefaultAzureCredential, since it really only works on Windows, and seems to cause issues on other systems.

For consistency, we should exclude the SharedTokenCacheCredential from our default credential.

Merged PR for azure-sdk-for-net to remove SharedTokenCacheCredential from default: Azure/azure-sdk-for-net#16615
Related Issue: Azure/azure-sdk-for-net#17052

[vxfield]

@xinyi-joffre, @anpaz: FYI