Update Input System version in package.json

Author: graham-huws

com.unity.template-hd/Packages/com.unity.template.hd/package.json

@@ -10,7 +10,7 @@
     "com.unity.collab-proxy": "2.0.5",
     "com.unity.feature.development": "1.0.2",
     "com.unity.cinemachine": "2.9.5",
-    "com.unity.inputsystem": "1.7.0",
+    "com.unity.inputsystem": "1.8.1",
     "com.unity.learn.iet-framework": "3.1.3",
     "com.unity.render-pipelines.high-definition": "16.0.2",
     "com.unity.timeline": "1.8.3",