zstd: use shared linkage, remove `zlib` dependency
zstd: use shared linkage, remove `zlib` dependency

This formula has no linkage with `zlib` on macOS and Linux, so it seems
likely that `zlib` is not actually needed.

Additionally, set `ZSTD_PROGRAMS_LINK_SHARED` so that the `zstd` binary
links dynamically with `libzstd` instead of linking statically.

Shared linking decreases the size of the `zstd` binary and creates
opportunities for more efficient use of system resources (at the minor
cost of overhead care of dynamic linking).

Neither of these changes are probably enough to warrant a revision bump,
but building new bottles won't hurt.

Closes #99766.

Signed-off-by: Michael Cho <ad37dc0e034c3938811c0096de6272abd124db31@users.noreply.github.com>
Signed-off-by: BrewTestBot <8a898ee6867e4f2028e63d2a6319b2224641c06c@users.noreply.github.com>

stgraber/homebrew-core,adam-moss/homebrew-core,makigumo/homebrew-core,chrisfinazzo/homebrew-core,lemzwerg/homebrew-core,nbari/homebrew-core,zyedidia/homebrew-core,nbari/homebrew-core,adam-moss/homebrew-core,zyedidia/homebrew-core,Homebrew/homebrew-core,nandub/homebrew-core,chrisfinazzo/homebrew-core,Homebrew/homebrew-core,filcab/homebrew-core,stgraber/homebrew-core,nandub/homebrew-core,lemzwerg/homebrew-core,sjackman/homebrew-core,sjackman/homebrew-core,filcab/homebrew-core,makigumo/homebrew-core