Remove --check-lock when installing deps for phoenix_app

On elixir < 1.17 --depth option is not included in mix.lock which makes
running deps.get alter mix.lock and so we can't use --check-lock

Author: solnic

.github/workflows/main.yml

@@ -65,7 +65,7 @@ jobs:
       run: |
         mix do deps.get --check-locked, deps.compile
         cd test_integrations/phoenix_app
-        mix do deps.get --check-locked, deps.compile
+        mix do deps.get, deps.compile
 
     - name: Save Mix dependencies cache
       uses: actions/cache/save@v4