Dedupe libvips-42.dll for windows users

Feature request

As Windows doesn’t come with libvips, Sharp convenient bundles it in as a .dll file, but it bundles it in twice: once in build/release and then again in vendor/8.13.2/win32-x64/lib. Given that it’s a whopping 21Mb, deduplicating that would be an excellent idea. (The same applies to libglib-2.0-0.dll, libvips-cpp.dll, and libgobject-2.0-0.dll, which take up a combined additional 2Mb)

The two most obvious options I can think of would be:

• remove the vendor dir from the Windows build before packing up the release, or
• make the .dll files in build/release Windows symlinks instead of real files.

Either would cut the Windows release size in half.

[lovell]

@Julusian I think it will be OK as prebuild-install won’t delete anything. Running node-gyp will delete build, hence the current implementation that always copies the latest DLL files.

Perhaps, as part of this proposal, we should also add logic to dll-copy that verifies build has the expected files, especially if vendor is empty?

[Julusian]

How will removing these duplicate files interact with prebuild-install?

It is not uncommon for prebuild-install to be run each time an electron build is produced. In one project I have made it manually invoke the postinstall commands, to allow for cross-compiling the electron app https://github.com/bitfocus/companion/blob/master/tools/build_prepare.mjs