Inline arguments and sample less

Co-authored-by: Ricardo Vieira <28983449+ricardoV94@users.noreply.github.com>

tests/sampling/test_forward.py

@@ -562,15 +562,15 @@ def test_external_trace(self):
         assert list(ppc.keys()) == ["a"]
 
     def test_external_trace_det(self):
-        nchains = 2
-        ndraws = 500
         with pm.Model() as model:
             mu = pm.Normal("mu", 0.0, 1.0)
             a = pm.Normal("a", mu=mu, sigma=1, observed=0.0)
             b = pm.Deterministic("b", a + 1)
             trace = pm.sample(
-                draws=ndraws,
-                chains=nchains,
+               tune=50,
+                draws=50,
+                chains=1,
+                compute_convergence_checks=False
             )
 
         # test that trace is used in ppc