ci(external_libs): Add EthernetESP32 to ext. libraries compilation test (#9747)

.github/workflows/lib.json

@@ -35,6 +35,14 @@
             "~/Arduino/libraries/ESPAsyncWebServer/examples/simple_server/simple_server.ino"
         ]
     },
+    {
+        "name": "EthernetESP32",
+        "exclude_targets": [],
+        "sketch_path": [
+            "~/Arduino/libraries/EthernetESP32/examples/LegacyEthernetTest/LegacyEthernetTest.ino",
+            "~/Arduino/libraries/EthernetESP32/examples/TwoEthernets/TwoEthernets.ino"
+        ]
+    },
     {
         "name": "FastLED",
         "exclude_targets": [],