test: do not test system subtype warning in independent_variables

Author: AayushSabharwal

test/abstractsystem.jl

@@ -8,7 +8,6 @@ struct MyNLS <: MT.AbstractSystem
     name::Any
     systems::Any
 end
-@test_logs (:warn,) tmp=independent_variables(MyNLS("sys", []))
 tmp = independent_variables(MyNLS("sys", []))
 @test tmp == []
 
@@ -17,7 +16,6 @@ struct MyTDS <: MT.AbstractSystem
     name::Any
     systems::Any
 end
-@test_logs (:warn,) iv=independent_variables(MyTDS(t, "sys", []))
 iv = independent_variables(MyTDS(t, "sys", []))
 @test all(isequal.(iv, [t]))
 
@@ -26,6 +24,5 @@ struct MyMVS <: MT.AbstractSystem
     name::Any
     systems::Any
 end
-@test_logs (:warn,) ivs=independent_variables(MyMVS([t, x], "sys", []))
 ivs = independent_variables(MyMVS([t, x], "sys", []))
 @test all(isequal.(ivs, [t, x]))