Add nested precomp highlight debug

[IanButterworth]

Fixes the pkgimage.mk stdlib dep tree which was slightly wrong and causing some nested precompilation

And adds debugs that identified the above issue, and have been useful for debugging #53081

i.e.

% JULIA_DEBUG=nested_precomp ./julia -q

(@v1.11) pkg> precompile
Precompiling project...
  103 dependencies successfully precompiled in 34 seconds. 40 already precompiled.
  2 dependencies had output during precompilation:
┌ FillArrays → FillArraysPDMatsExt
│  ┌ Debug: Nested precompilation: FillArraysPDMatsExt > FillArraysSparseArraysExt
│  └ @ Base loading.jl:2520
└  
┌ Symbolics → SymbolicsPreallocationToolsExt
│  ┌ Debug: Nested precompilation: SymbolicsPreallocationToolsExt > SymbolicsForwardDiffExt
│  └ @ Base loading.jl:2520
│  ┌ Warning: Module SymbolicsPreallocationToolsExt with build ID ffffffff-ffff-ffff-0008-f643010bcdb7 is missing from the cache.
│  │ This may mean SymbolicsPreallocationToolsExt [d479e226-fb54-5ebe-a75e-a7af7f39127f] does not support precompilation but is imported by a module that does.
│  └ @ Base loading.jl:2121
│  ┌ Error: Error during loading of extension SymbolicsPreallocationToolsExt of Symbolics, use `Base.retry_load_extensions()` to retry.

[vchuravy]

Should we fast-track f05f93d first?

[IanButterworth]

#53112 is the follow-on for this