Remove outdated Julia version checks from tests

Since Julia v1.10 is now the LTS version, remove conditional code for:
- Julia v1.7 check in test/clock.jl
- Julia v1.5 check in test/direct.jl
- Julia v1.8 check in test/input_output_handling.jl

These version checks are no longer necessary as the minimum supported Julia version is now well above these thresholds.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: claude

test/clock.jl

@@ -298,43 +298,41 @@ eqs = [yd ~ Sample(dt)(y)
     ss = mtkcompile(cl)
     ss_nosplit = mtkcompile(cl; split = false)
 
-    if VERSION >= v"1.7"
-        prob = ODEProblem(ss, [x => 0.0, kp => 1.0], (0.0, 1.0))
-        prob_nosplit = ODEProblem(ss_nosplit, [x => 0.0, kp => 1.0], (0.0, 1.0))
-        sol = solve(prob, Tsit5(), kwargshandle = KeywordArgSilent)
-        sol_nosplit = solve(prob_nosplit, Tsit5(), kwargshandle = KeywordArgSilent)
-
-        function foo!(dx, x, p, t)
-            kp, ud1, ud2 = p
-            dx[1] = -x[1] + ud1 + ud2
-        end
+    prob = ODEProblem(ss, [x => 0.0, kp => 1.0], (0.0, 1.0))
+    prob_nosplit = ODEProblem(ss_nosplit, [x => 0.0, kp => 1.0], (0.0, 1.0))
+    sol = solve(prob, Tsit5(), kwargshandle = KeywordArgSilent)
+    sol_nosplit = solve(prob_nosplit, Tsit5(), kwargshandle = KeywordArgSilent)
 
-        function affect1!(integrator)
-            kp = integrator.p[1]
-            y = integrator.u[1]
-            r = 1.0
-            ud1 = kp * (r - y)
-            integrator.p[2] = ud1
-            nothing
-        end
-        function affect2!(integrator)
-            kp = integrator.p[1]
-            y = integrator.u[1]
-            r = 1.0
-            ud2 = kp * (r - y)
-            integrator.p[3] = ud2
-            nothing
-        end
-        cb1 = PeriodicCallback(affect1!, dt; final_affect = true, initial_affect = true)
-        cb2 = PeriodicCallback(affect2!, dt2; final_affect = true, initial_affect = true)
-        cb = CallbackSet(cb1, cb2)
-        #                                           kp   ud1  ud2
-        prob = ODEProblem(foo!, [0.0], (0.0, 1.0), [1.0, 1.0, 1.0], callback = cb)
-        sol2 = solve(prob, Tsit5())
-
-        @test sol.u≈sol2.u atol=1e-6
-        @test sol_nosplit.u≈sol2.u atol=1e-6
+    function foo!(dx, x, p, t)
+        kp, ud1, ud2 = p
+        dx[1] = -x[1] + ud1 + ud2
+    end
+
+    function affect1!(integrator)
+        kp = integrator.p[1]
+        y = integrator.u[1]
+        r = 1.0
+        ud1 = kp * (r - y)
+        integrator.p[2] = ud1
+        nothing
     end
+    function affect2!(integrator)
+        kp = integrator.p[1]
+        y = integrator.u[1]
+        r = 1.0
+        ud2 = kp * (r - y)
+        integrator.p[3] = ud2
+        nothing
+    end
+    cb1 = PeriodicCallback(affect1!, dt; final_affect = true, initial_affect = true)
+    cb2 = PeriodicCallback(affect2!, dt2; final_affect = true, initial_affect = true)
+    cb = CallbackSet(cb1, cb2)
+    #                                           kp   ud1  ud2
+    prob = ODEProblem(foo!, [0.0], (0.0, 1.0), [1.0, 1.0, 1.0], callback = cb)
+    sol2 = solve(prob, Tsit5())
+
+    @test sol.u≈sol2.u atol=1e-6
+    @test sol_nosplit.u≈sol2.u atol=1e-6
 
     ##
     @info "Testing hybrid system with components"

test/direct.jl

@@ -240,22 +240,20 @@ kwargs = (; name = 3)
 @test cool_name[1] == (42,)
 @test collect(cool_name[2]) == [:name => 3]
 
-if VERSION >= v"1.5"
-    name = 3
-    @named cool_name = foo(42; name)
-    @test cool_name[1] == (42,)
-    @test collect(cool_name[2]) == [:name => name]
-    @named cool_name = foo(; name)
-    @test collect(cool_name) == [:name => name]
-
-    ff = 3
-    @named cool_name = foo(42; ff)
-    @test cool_name[1] == (42,)
-    @test collect(cool_name[2]) == [pp; :ff => ff]
-
-    @named cool_name = foo(; ff)
-    @test collect(cool_name) == [pp; :ff => ff]
-end
+name = 3
+@named cool_name = foo(42; name)
+@test cool_name[1] == (42,)
+@test collect(cool_name[2]) == [:name => name]
+@named cool_name = foo(; name)
+@test collect(cool_name) == [:name => name]
+
+ff = 3
+@named cool_name = foo(42; ff)
+@test cool_name[1] == (42,)
+@test collect(cool_name[2]) == [pp; :ff => ff]
+
+@named cool_name = foo(; ff)
+@test collect(cool_name) == [pp; :ff => ff]
 
 foo(i; name) = (; i, name)
 @named goo[1:3] = foo(10)

test/input_output_handling.jl

@@ -8,10 +8,8 @@ using ModelingToolkit: t_nounits as t, D_nounits as D
 eqs = [D(xx) ~ some_input]
 @named model = System(eqs, t)
 @test_throws ExtraVariablesSystemException mtkcompile(model)
-if VERSION >= v"1.8"
-    err = "In particular, the unset input(s) are:\n some_input(t)"
-    @test_throws err mtkcompile(model)
-end
+err = "In particular, the unset input(s) are:\n some_input(t)"
+@test_throws err mtkcompile(model)
 
 # Test input handling
 @variables x(t) u(t) [input = true] v(t)[1:2] [input = true]