Merge pull request #461 from SciML/compathelper/new_version/2021-12-23-04-29-22-350-04278879101

CompatHelper: bump compat for ModelingToolkit to 8, (keep existing compat)

Author: ChrisRackauckas

Project.toml

@@ -53,7 +53,7 @@ Flux = "0.12.6"
 ForwardDiff = "0.10"
 GalacticOptim = "1, 2"
 IfElse = "0.1"
-ModelingToolkit = "7"
+ModelingToolkit = "7, 8"
 Optim = "1.0"
 Quadrature = "1.5"
 QuasiMonteCarlo = "0.2.1"