fix: add warning for when arch is supplied but version is missing

src/main.ts

@@ -17,6 +17,15 @@ export async function run() {
     }
 
     let arch = core.getInput('node-arch');
+
+    // if node-arch supplied but node-version is not
+    // if we don't throw a warning, the already installed x64 node will be used which is not probably what user meant.
+    if (arch && !version) {
+      core.warning(
+        '`node-arch` is provided but `node-version` is missing. This results in using an already installed x64 node which is not probably what you meant. To fix this, provide `node-arch` in combination with `node-version`'
+      );
+    }
+
     if (!arch) {
       arch = os.arch();
     }