remove DataInterpolationsv6 and update tests

Author: oscarddssmith

Project.toml

@@ -98,7 +98,7 @@ Combinatorics = "1"
 CommonSolve = "0.2.4"
 Compat = "3.42, 4"
 ConstructionBase = "1"
-DataInterpolations = "6.4, 7, 8"
+DataInterpolations = "7, 8"
 DataStructures = "0.17, 0.18"
 DeepDiffs = "1"
 DelayDiffEq = "5.50"

test/split_parameters.jl

@@ -257,7 +257,7 @@ end
 
     @testset "Concrete function type" begin
         ts = 0.0:0.1:1.0
-        interp = LinearInterpolation(ts .^ 2, ts; extrapolate = true)
+        interp = LinearInterpolation(ts .^ 2, ts; extrapolation = ExtrapolationType.Extension)
         @variables x(t)
         @parameters (fn::typeof(interp))(..)
         @mtkcompile sys = System(D(x) ~ fn(x), t)
@@ -267,7 +267,7 @@ end
         @inferred getter(prob)
         @inferred prob.f(prob.u0, prob.p, prob.tspan[1])
         @test_nowarn sol = solve(prob, Tsit5())
-        @test_nowarn prob.ps[fn] = LinearInterpolation(ts .^ 3, ts; extrapolate = true)
+        @test_nowarn prob.ps[fn] = LinearInterpolation(ts .^ 3, ts; extrapolation = ExtrapolationType.Extension)
         @test_nowarn sol = solve(prob)
     end
 end