Short answer regarding vlc:
vlc.tcz is fine (it depends on lua-5.3-lib.tcz which is still present in the repo) but vlc-dev.tcz should be removed from the TCL15 x86_64 repo until vlc is recompiled against lua-5.4.
Long answer regarding vlc:
I maintain some of the lua packages, so can shed some light on the problem.
lua-5.3.tcz and lua-5.3-dev.tcz no longer exist in the x86_64 repo because they have been superceded by lua-5.4.tcz and lua-5.4-dev.tcz.
In lua, different from most software projects, x.y -> x.y+1 denotes a major version change (which should be considered ABI-incompatible), so it's probably not okay to just edit vlc-dev.tcz.dep to depend on lua-5.4.tcz and lua-5.4-dev.tcz instead.