Use ConfigureAwait(false) on ConnectionMultiplexerFactory (#39865)

Author: Kahbazi

src/Caching/StackExchangeRedis/src/RedisCache.cs

@@ -261,7 +261,7 @@ private void Connect()
                 }
                 else
                 {
-                    _connection = await _options.ConnectionMultiplexerFactory();
+                    _connection = await _options.ConnectionMultiplexerFactory().ConfigureAwait(false);
                 }
 
                 PrepareConnection();