CompatHelper: bump compat for DelayDiffEq to 6, (keep existing compat)

Author: CompatHelper Julia

Project.toml

@@ -1,8 +1,8 @@
 name = "ControlSystems"
 uuid = "a6e380b2-a6ca-5380-bf3e-84a91bcd477e"
+version = "1.15.2"
 authors = ["Dept. Automatic Control, Lund University"]
 repo = "https://github.com/JuliaControl/ControlSystems.jl.git"
-version = "1.15.2"
 
 [deps]
 ControlSystemsBase = "aaaaaaaa-a6ca-5380-bf3e-84a91bcd477e"
@@ -22,7 +22,7 @@ StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
 [compat]
 Aqua = "0.5"
 ControlSystemsBase = "1.3"
-DelayDiffEq = "5.31"
+DelayDiffEq = "5.31, 6"
 DiffEqBase = "6"
 DiffEqCallbacks = "2.16, 3, 4"
 ForwardDiff = "0.10, 1"