Remove unused package

Packages/manifest.json

@@ -17,7 +17,6 @@
     "com.unity.render-pipelines.universal": "17.2.0",
     "com.unity.test-framework": "1.5.1",
     "com.unity.timeline": "1.8.9",
-    "com.unity.toolchain.linux-x86_64": "2.0.10",
     "com.unity.toolchain.macos-arm64-linux-x86_64": "2.0.4",
     "com.unity.ugui": "2.0.0",
     "com.unity.visualscripting": "1.9.8",

Packages/packages-lock.json

@@ -293,16 +293,6 @@
       },
       "url": "https://packages.unity.com"
     },
-    "com.unity.toolchain.linux-x86_64": {
-      "version": "2.0.10",
-      "depth": 0,
-      "source": "registry",
-      "dependencies": {
-        "com.unity.sysroot": "2.0.10",
-        "com.unity.sysroot.linux-x86_64": "2.0.9"
-      },
-      "url": "https://packages.unity.com"
-    },
     "com.unity.toolchain.macos-arm64-linux-x86_64": {
       "version": "2.0.4",
       "depth": 0,