[libigl] Always install as header-only lib

[FabienPean]

• Changes comply with the maintainer guide
• SHA512s are updated for each updated download
• The "supports" clause reflects platforms that may be fixed by this new version
• Any fixed CI baseline entries are removed from that file.
• Any patches that are no longer applied are deleted from the port's directory.
• The version database is fixed by rerunning ./vcpkg x-add-version --all and committing the result.
• Only one version is added to each modified port's versions file.

See the discussion here: #27963 (comment)

Pasting the reply again here for completeness:

There is clearly something happening here that is not just copying headers. Things like LIBIGL_USE_STATIC_LIBRARY suggest that there is in fact a static library and that this thing is not header only. Can you explain why / how this is header only despite the port clearly doing not header only things?

With this option, the library is explicitly instantiating some templates into a static library, but, it also removes all definition of the templated functions... Building with LIBIGL_USE_STATIC_LIBRARY is fundamentally different from standard expectation when considering static/shared. It was the case then #14888, it is still applicable now after checking the repo.

Ultimately this means using libigl after this PR with a static vcpkg triplet would break users relying on types outside the ones allowed by libigl devs.

@BillyONeal @FrankXie05

[FabienPean]

More problems with v2.4.0, please follow the related issue #30621