It appears you are hitting Failing to precompile Plots due to LoadError (Mac edition) - #7 by jeffzwe.
You can open a ticket in Issues · JuliaPackaging/Yggdrasil · GitHub about Yggdrasil/build_tarballs.jl at master · JuliaPackaging/Yggdrasil · GitHub if you seek a solution to this.
And another related issue: Qt-based JLLs fail to precompile on old macOS; affects GR and Plots.jl · Issue #2883 · JuliaPackaging/Yggdrasil · GitHub.