Remove packets_for_test fixture dependency for proxy arp enabled (sonic-net#21803)

* Remove packets_for_test fixture dependency for proxy arp enabled

Fixing issue:
sonic-net#21801

Determine the ip version from the test name to remove teh dependency on
packets_for_test.

Signed-off-by: Justin Wong <jvwong@arista.com>

Author: justin-wong-ce

tests/arp/conftest.py

@@ -282,7 +282,7 @@ def ip_and_intf_info(config_facts, intfs_for_test, ptfhost, ptfadapter):
 
 
 @pytest.fixture
-def proxy_arp_enabled(packets_for_test, rand_selected_dut, config_facts):
+def proxy_arp_enabled(request, rand_selected_dut, config_facts):
     """
     Tries to enable proxy ARP for each VLAN on the ToR
 
@@ -303,7 +303,6 @@ def proxy_arp_enabled(packets_for_test, rand_selected_dut, config_facts):
     vlan_ids = [vlans[vlan]['vlanid'] for vlan in list(vlans.keys())]
     old_proxy_arp_vals = {}
     new_proxy_arp_vals = []
-    ip_version, _, _ = packets_for_test
 
     # Enable proxy ARP/NDP for the VLANs on the DUT
     for vid in vlan_ids:
@@ -316,7 +315,7 @@ def proxy_arp_enabled(packets_for_test, rand_selected_dut, config_facts):
         new_proxy_arp_res = duthost.shell(proxy_arp_check_cmd.format(vid))
         new_proxy_arp_vals.append(new_proxy_arp_res['stdout'])
 
-    if ip_version == 'v6':
+    if 'ipv6' in request.node.name:
         # Allow time for ndppd to reset and startup
         time.sleep(30)