update test execution dt and runtime

Author: VeckoTheGecko

tests/test_interpolation.py

@@ -172,7 +172,7 @@ def DeleteParticle(particle, fieldset, time):
             particle.delete()
 
     for pset in [pset_scipy, pset_jit]:
-        pset.execute([AdvectionRK4_3D, DeleteParticle], runtime=4e-3, dt=1e-3)
+        pset.execute([AdvectionRK4_3D, DeleteParticle], runtime=4, dt=1)
 
     tol = 1e-8
     for i in range(len(pset_scipy)):