AzureServiceTokenCredential until https://github.com/Azure/azure-sdk-for-net/issues/8934 gets fixed

AzureKeyVaultClients.cs

using Azure.Security.KeyVault.Keys;
using Azure.Security.KeyVault.Secrets;
using System;

namespace Common
{
    public class AzureKeyVaultClients : IAzureKeyVaultClients
    {
        private AzureKeyVaultTokenCredential _azureKeyVaultTokenCredential;

        public AzureKeyVaultClients(AzureKeyVaultTokenCredential azureKeyVaultTokenCredential)
        {
            _azureKeyVaultTokenCredential = azureKeyVaultTokenCredential;
        }

        public SecretClient CreateSecretClient(string keyVaultUrl)
        {
            return new SecretClient(vaultUri: new Uri(keyVaultUrl), credential: _azureKeyVaultTokenCredential);

        }

        public KeyClient CreateKeyClient(string keyVaultUrl)
        {
            return new KeyClient(vaultUri: new Uri(keyVaultUrl), credential: _azureKeyVaultTokenCredential);
        }
    }
}

AzureKeyVaultTokenCredential.cs

namespace Common
{
    public class AzureKeyVaultTokenCredential : AzureServiceTokenCredential
    {
        public AzureKeyVaultTokenCredential() : base("https://vault.azure.net")
        {
        }
    }
}

AzureServiceTokenCredential.cs

using Azure.Core;
using Microsoft.Azure.Services.AppAuthentication;
using System;
using System.Threading;
using System.Threading.Tasks;

namespace Common
{
    public class AzureServiceTokenCredential : TokenCredential
    {
        public AzureServiceTokenCredential(string endPoint)
        {
            if (string.IsNullOrWhiteSpace(endPoint))
            {
                throw new ArgumentException("message", nameof(endPoint));
            }

            EndPoint = endPoint;
        }

        public string EndPoint { get; }

        public override AccessToken GetToken(TokenRequestContext requestContext, CancellationToken cancellationToken)
        {
            var token = GetTokenAsync(requestContext, cancellationToken).GetAwaiter().GetResult();
            return token;
        }

        public override ValueTask<AccessToken> GetTokenAsync(TokenRequestContext requestContext, CancellationToken cancellationToken)
        {
            var tokenProvider = new AzureServiceTokenProvider();
            return new ValueTask<AccessToken>(tokenProvider
                .GetAccessTokenAsync(EndPoint, null, cancellationToken)
                .ContinueWith(task => {
                    return new AccessToken(task.Result, DateTimeOffset.MaxValue);
                }));
        }
    }
}