precompilepkgs: make the circular dep report prettier

[IanButterworth]

Was e.g.

┌ Warning: Circular dependency detected. Precompilation will be skipped for:
│   Base.PkgId(Base.UUID("eb0c05c4-6780-5852-a67e-5d31d2970b9a"), "ArrayInterfaceTrackerExt")
│   Base.PkgId(Base.UUID("f517fe37-dbe3-4b94-8317-1923a5111588"), "Polyester")
│   Base.PkgId(Base.UUID("0d7ed370-da01-4f52-bd93-41d350b8b718"), "StaticArrayInterface")
│   Base.PkgId(Base.UUID("6a4ca0a5-0e36-4168-a932-d9be78d558f1"), "AcceleratedKernels")
│   Base.PkgId(Base.UUID("244f68ed-b92b-5712-87ae-6c617c41e16a"), "NNlibAMDGPUExt")
│   Base.PkgId(Base.UUID("06b0261c-7a9b-5753-9bdf-fd6840237b4a"), "StaticArrayInterfaceStaticArraysExt")
│   Base.PkgId(Base.UUID("21141c5a-9bdb-4563-92ae-f87d6854732e"), "AMDGPU")
│   Base.PkgId(Base.UUID("9f7883ad-71c0-57eb-9f7f-b5c9e6d3789c"), "Tracker")
└ @ Base.Precompilation precompilation.jl:511

Now

julia> Pkg.precompile()
┌ Warning: Circular dependency detected. Precompilation will be skipped for:
│   CircularDep3
│   CircularDep2
│   CircularDep1
│   Foo → CircularExt
└ @ Base.Precompilation precompilation.jl:572