Adjust to upcoming Julia 1.10 changes

[fingolfin]

Julia will soon (I hope) merge JuliaLang/julia#44527 which will break GAP.jl; but everything is in place to fix that. To ensure the switch will be as quick and painless as possible, I am noting down what needs to be done here. (Also, once the breakage starts I can just point people here to explain what's going on).

• merge Use jl_reinit_foreign_type if available gap-system/gap#5224
• update libjulia_jll with new post-merge Julia master: Update libjulia for latest master JuliaPackaging/Yggdrasil#5934
• update GAP_jll ...
  • using the new libjulia_jll
  • with the patch from Use jl_reinit_foreign_type if available gap-system/gap#5224 applied
  • modified so that the init_block is not set resp. executed for Julia >= 1.10 with jl_reinit_foreign_type (which may eventually include 1.9, as there are plans to backport this)
• merge PR Use jl_reinit_foreign_type if available #845
• release new GAP.jl using thew new GAP_jll