Bump actions/checkout from 3 to 4 (#22)

Author: dependabot[bot]

.github/workflows/go.yml

@@ -17,7 +17,7 @@ jobs:
 
     steps:
     - name: Check out code
-      uses: actions/checkout@v3
+      uses: actions/checkout@v4
     # https://github.com/actions/setup-go
     - name: Use Go ${{ matrix.go_version }}
       timeout-minutes: 3

.github/workflows/release.yml

@@ -17,7 +17,7 @@ jobs:
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
 
       - name: Setup ENV
         # https://docs.github.com/en/free-pro-team@latest/actions/reference/workflow-commands-for-github-actions#setting-an-environment-variable