mailmap: update replacements

[skip ci]

.mailmap

@@ -1,2 +1,4 @@
-Unknwon <[email protected]> <[email protected]>
-Unknwon <[email protected]> 无闻 <[email protected]>
+Joe Chen <[email protected]> Unknwon <[email protected]>
+Joe Chen <[email protected]> 无闻 <[email protected]>
+Joe Chen <[email protected]> ᴜɴᴋɴᴡᴏɴ <[email protected]>
+Joe Chen <[email protected]> ᴜɴᴋɴᴡᴏɴ <[email protected]>