Raise ModelingToolkitBase DelayDiffEq floor (#4994)

Co-authored-by: ChrisRackauckas-Claude <accounts@chrisrackauckas.com>

Author: ChrisRackauckas-Claude

lib/ModelingToolkitBase/Project.toml

@@ -113,7 +113,7 @@ ConstructionBase = "1"
 ControlSystemsBase = "1"
 DataInterpolations = "9"
 DataStructures = "0.18, 0.19"
-DelayDiffEq = "6"
+DelayDiffEq = "6.1"
 DiffEqBase = "7.14"
 DiffEqCallbacks = "4"
 DiffEqNoiseProcess = "5"