https://downloads.mysql.com/archives/community/
There you select 5.7.36 download the Windows (x86, 32-bit), ZIP Archive and there you have your latest libmysql.dll in 32-bit and yes the "caching sha2 authentication" works, I testet it, and it works with MySQL 8.0! So this is the best solution for me.
A real MySQL 8.0 libmysql.dll in 32-bit is not available.