vips: build with mozjpeg
vips: build with mozjpeg

This updates the vips build to compile against mozjpeg instead of
regular libjpeg.

VIPS supports several additional JPEG encoding options and provides
better compression quality when it's built against mozjpeg[1].

mozjpeg is slower than libjpeg-turbo, but can compress better, with a
rich range of options. The VIPS maintainer jcupitt seems to be of the
opinion that the homebrew build of VIPS should should favour
functionality over production considerations[2], so better compression
functionality in exchange for slower execution seems a fair tradeoff.

1: https://jcupitt.github.io/libvips/API/current/VipsForeignSave.html#vips-jpegsave
2: https://github.com/Homebrew/homebrew-core/pull/36700#issuecomment-460662817

Closes #47237.

Signed-off-by: Rui Chen <5fd29470147430022ff146db88de16ee91dea376@gmail.com>

spaam/homebrew-core,spaam/homebrew-core,nbari/homebrew-core,dsXLII/homebrew-core,Moisan/homebrew-core,nbari/homebrew-core,nandub/homebrew-core,edporras/homebrew-core,mvitz/homebrew-core,mahori/homebrew-core,lembacon/homebrew-core,jvillard/homebrew-core,sjackman/homebrew-core,JCount/homebrew-core,Linuxbrew/homebrew-core,zyedidia/homebrew-core,maxim-belkin/homebrew-core,zyedidia/homebrew-core,stgraber/homebrew-core,mbcoguno/homebrew-core,nandub/homebrew-core,stgraber/homebrew-core,makigumo/homebrew-core,mbcoguno/homebrew-core,uyjulian/homebrew-core,BrewTestBot/homebrew-core,mahori/homebrew-core,jvillard/homebrew-core,lembacon/homebrew-core,mvitz/homebrew-core,LinuxbrewTestBot/homebrew-core,mfikes/homebrew-core,aabdnn/homebrew-core,LinuxbrewTestBot/homebrew-core,sjackman/homebrew-core,rwhogg/homebrew-core,lemzwerg/homebrew-core,jvillard/homebrew-core,BrewTestBot/homebrew-core,adam-moss/homebrew-core,Homebrew/homebrew-core,cblecker/homebrew-core,aabdnn/homebrew-core,chrisfinazzo/homebrew-core,rwhogg/homebrew-core,filcab/homebrew-core,edporras/homebrew-core,chrisfinazzo/homebrew-core,makigumo/homebrew-core,dsXLII/homebrew-core,adam-moss/homebrew-core,Homebrew/homebrew-core,Moisan/homebrew-core,jabenninghoff/homebrew-core,mfikes/homebrew-core,mbcoguno/homebrew-core,Linuxbrew/homebrew-core,uyjulian/homebrew-core,filcab/homebrew-core,lembacon/homebrew-core,mvitz/homebrew-core,maxim-belkin/homebrew-core,jabenninghoff/homebrew-core,JCount/homebrew-core,lemzwerg/homebrew-core,cblecker/homebrew-core