replace zig1.wasm to the removal of BoundFn

This also no longer uses zstd compression on this file. The reasoning
for this is:

 * It has been demonstrated that the release tarballs are actually
   smaller if zig1.wasm gets compressed along with the other files
   rather than separately compressed.

 * More importantly, leaving zig1.wasm uncompressed may result in a
   smaller git repository size, since the repository as a whole could
   have savings across the multiple versions of zig1.wasm, which would
   not be possible if each one was independently compressed.

 * When in doubt, do what is simpler, which is to not have this extra
   zstd mechanism. This will remove the only "vendored" code from our
   build process, which is a nice property to have.

Co-authored-by: Andrew Kelley <[email protected]>

Author: Vexu