Ambiguity check errors on Julia 1.0: type UnionAll has no field name

[devmotion]

In JuliaStats/StatsBase.jl#866, I observed test errors of the ambiguity check on Julia 1.0 which seem to be caused by a bug in Aqua (see, e.g., https://github.com/JuliaStats/StatsBase.jl/actions/runs/5298486934/jobs/9590870427?pr=866):

┌ Error: Failed to obtain a function from `Method`.
│   exception =
│    type UnionAll has no field name
│    Stacktrace:
│     [1] getproperty at ./sysimg.jl:15 [inlined]
│     [2] getobj(::Method) at /home/runner/.julia/packages/Aqua/BhBic/src/ambiguities.jl:168
...

[fingolfin]

Thank you for the report. I think this is a duplicate of issue #49.