fix: iOS setting to 26 (#34)

Author: riteshshukla04

.github/actions/test-library-on-nightly/action.yml

@@ -26,7 +26,7 @@ runs:
       if: ${{ inputs.platform == 'ios' }}
       uses: maxim-lobanov/setup-xcode@v1
       with:
-        xcode-version: latest-stable
+        xcode-version: 16.4.0
     - name: Build iOS
       shell: bash
       if: ${{ inputs.platform == 'ios' }}