Fix JET warning in `artifact_meta` (#60507)
`unpack_platform` might return nothing in case of an error.
Together with PR #60506 and my previous changes, when applied to
release-1.12, the JET report for GAP.jl is now free of reports. Well, if
I filter out certain "unavoidable issues":
```julia
using Revise, JET, AbstractAlgebra, GAP
struct AnyFrameMethod <: ReportMatcher
m::Union{Function,Method,Symbol}
end
function JET.match_report(matcher::AnyFrameMethod, @nospecialize(report::JET.InferenceErrorReport))
# check all VirtualFrames in the VirtualStackTrace for a match to the specified method
m = matcher.m
if m isa Symbol
return any(vf -> vf.linfo.def.name === m, report.vst)
elseif m isa Method
return any(vf -> vf.linfo.def === m, report.vst)
else # if m isa Function
return any(vf -> vf.linfo.def in methods(m), report.vst)
end
end
report_package(GAP; ignored_modules=[AnyFrameMethod(:is_loaded_directly)])
```
