test_xgmii_phy: remove vcd dump of XGMII test

Removes a slightly inappropriately named VCD dump created by the XGMII
tests which may or may not have been a result of some frustration
during the test implementation. :)

Fixes: 8da0423f64 ("Add XGMII PHY tests based on captured ...")
Signed-off-by: Leon Schuermann <leon@is.currently.online>

test/test_xgmii_phy.py

@@ -546,7 +546,6 @@ class TestXGMIIPHY(unittest.TestCase):
                         and not xgmii_tx_collector.collecting,
                 ),
             ],
-            vcd_name="xgmii_fuuuuuck.vcd",
         )
 
         self.assertTrue(