Update libxp2p_ios.yml

Author: tonychanchen

.github/workflows/libxp2p_ios.yml

@@ -14,7 +14,10 @@ jobs:
       uses: actions/checkout@v3
       with:
         fetch-depth: 0
-    
+    - name: Setup cmake
+      uses: jwlawson/[email protected]
+      with:
+        cmake-version: '3.17.0'
     - name: build libenet
       if: startsWith(github.event.ref, 'refs/heads')
       run: |