fixup! test: test symbolic indexing of DDE solutions

Author: AayushSabharwal

test/dde.jl

@@ -119,7 +119,7 @@ sol = solve(prob, MethodOfSteps(Tsit5()))
 obsfn = ModelingToolkit.build_explicit_observed_function(
     sys, [sys.osc1.delx, sys.osc2.delx])
 obsval = @test_nowarn obsfn(sol.u[1], (_, t) -> sol(t), prob.p, sol.t[1])
-@test obsval ≈ sol(sol.t[1] - 0.01; idxs = [sys.osc1.x, sys.osc2.x])
+@test obsval ≈ [sol(sol.t[1] - sol.ps[sys.osc1.τ]; idxs = sys.osc1.x), sol(sol.t[1] - sol.ps[sys.osc2.τ]; idxs = sys.osc2.x)]
 #= TODO: Uncomment when implemented
 @test_nowarn sol[[sys.osc1.delx, sys.osc2.delx]]
 @test sol[sys.osc1.delx] ≈ sol(sol.t .- 0.01; idxs = sys.osc1.x)