fix to checkout submodules

Signed-off-by: Jun Kimura <[email protected]>

.github/workflows/test.yml

@@ -9,6 +9,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
         with:
+          submodules: recursive
           fetch-depth: 0
       - uses: actions/setup-go@v5
         with: