build: bump MTKStdlib compat

Author: AayushSabharwal

Project.toml

@@ -123,7 +123,7 @@ Libdl = "1"
 LinearAlgebra = "1"
 Logging = "1"
 MLStyle = "0.4.17"
-ModelingToolkitStandardLibrary = "2.19"
+ModelingToolkitStandardLibrary = "2.20"
 Moshi = "0.3"
 NaNMath = "0.3, 1"
 NonlinearSolve = "4.3"