update Aqua.jl tests (#118)

* update Aqua.jl tests

* bump version

Author: ranocha

Project.toml

@@ -1,7 +1,7 @@
 name = "RootedTrees"
 uuid = "47965b36-3f3e-11e9-0dcf-4570dfd42a8c"
 authors = ["Hendrik Ranocha <mail@ranocha.de> and contributors"]
-version = "2.19.1"
+version = "2.19.2"
 
 [deps]
 Latexify = "23fbe1c1-3f47-55db-b15f-69d7ec21a316"

test/runtests.jl

@@ -1722,6 +1722,8 @@ using Aqua: Aqua
     @testset "Aqua" begin
         Aqua.test_all(RootedTrees;
                       ambiguities = (; exclude = [getindex]),
+                      # Requires.jl is not loaded on new versions of Julia
+                      stale_deps = (; ignore = [:Requires]),
                       # New Project.toml tests fail on old versions of Julia
                       project_toml_formatting = false)