ci: update GitHub actions

Author: cclauss

.github/workflows/ci.yml

@@ -24,7 +24,7 @@ jobs:
     runs-on: ${{ matrix.platform }}
     steps:
     - name: Install Go
-      uses: actions/setup-go@v5
+      uses: actions/setup-go@v6
       with:
         go-version: ${{ matrix.go-version }}
 
@@ -34,7 +34,7 @@ jobs:
         git config --global core.eol lf
 
     - name: Checkout code
-      uses: actions/checkout@v4
+      uses: actions/checkout@v5
       with:
         fetch-depth: 1