test with vcpkg tag 2023.12.12 at commit id c8696863d371ab7f46e213d8f…

…5ca923c4aef2a00

drop fltk (upstream bugs) and use 7zip for testing

consume v4.1.2 for arm default triplet fix

add support for vcpkg-configuration.json's baseline

dont write files outside GH workspace

fix doc about how to run jest

readme fixups

fix log output

consume 2.0.13 packages

bump @actions/core to ^1.10.0 (#169)

set node16 handler for run-vcpkg@v7 (#167)

* set node16 handler for run-vcpkg@v7

* more recent vcpkg: 6ca56aeb457f033d344a7106cb3f9f1abf8f4e98

* more node16 support by bumping actions used in validation workflow

* bump @actions/core to get past warning: "The `save-state` command is deprecated and will be disabled soon."

* update deps for node&Co

* fix build error for unit test