test(uniswap): re-gate the FOX-pool tests on the emulator

These three tests lost their emulator guard, and without it they do not
fail on the emulator -- they HANG. The ETH/FOX pool contract is not in the
token table, and approving an unknown token contract never completes, so
the device keeps answering while the approval never finishes. The socket
timeout never fires because reads keep succeeding, so the job goes silent
until CI kills it on its no-output timeout, taking every later test with
it. That is why the suite died at 34% having reported no failure.

Gated rather than deleted, so the coverage comes back on its own once the
firmware completes this path. Known-token approves still run here, and on
hardware the app exercises this path.

Author: BitHighlander

tests/test_msg_ethereum_erc20_uniswap_liquidity.py

@@ -26,6 +26,24 @@
 from keepkeylib.tools import int_to_big_endian
 
 class TestMsgEthereumUniswaptxERC20(common.KeepKeyTest):
+
+    def setUp(self):
+        super(TestMsgEthereumUniswaptxERC20, self).setUp()
+        # Every test in this file approves or spends against the ETH/FOX pool,
+        # whose contract is NOT in the token table. Approving an unknown token
+        # contract does not complete on the emulator: the device never returns,
+        # so these tests HANG instead of failing, and CI kills the whole run on
+        # its no-output timeout -- taking every later test with it.
+        #
+        # This is a firmware-side limitation, not a gap in the tests. It is
+        # gated here rather than deleted so the coverage returns automatically
+        # once the firmware completes this path. Known-token approves
+        # (test_msg_ethereum_erc20_approve) run here and pass; on real hardware
+        # this path is exercised by the app.
+        if self.client.features.firmware_variant[0:8] == "Emulator":
+            self.skipTest(
+                "Uniswap liquidity against an unknown token contract does not "
+                "complete on the emulator")
 
     def test_sign_uni_approve_liquidity_ETH(self):
         self.requires_fullFeature()