fix CI fail - key can now be embstr or raw

Author: mgravell

tests/StackExchange.Redis.Tests/KeyTests.cs

@@ -182,8 +182,8 @@ public async Task KeyEncoding()
         db.KeyDelete(key, CommandFlags.FireAndForget);
         db.StringSet(key, "new value", flags: CommandFlags.FireAndForget);
 
-        Assert.Equal("embstr", db.KeyEncoding(key));
-        Assert.Equal("embstr", await db.KeyEncodingAsync(key));
+        Assert.True(db.KeyEncoding(key) is "embstr" or "raw"); // server-version dependent
+        Assert.True(await db.KeyEncodingAsync(key) is "embstr" or "raw");
 
         db.KeyDelete(key, CommandFlags.FireAndForget);
         db.ListLeftPush(key, "new value", flags: CommandFlags.FireAndForget);