build: Checkout source before Go setup.

This reverses the order of the checkout and setup actions so the setup
of Go itself is able to use the go.sum as a dependency as the newer
version expects.

.github/workflows/go.yml

@@ -11,12 +11,12 @@ jobs:
       matrix:
         go: ["1.19", "1.20"]
     steps:
+      - name: Check out source
+        uses: actions/checkout@c85c95e3d7251135ab7dc9ce3241c5835cc595a9 # v3.5.3
       - name: Set up Go
         uses: actions/setup-go@fac708d6674e30b6ba41289acaab6d4b75aa0753 # v4.0.1
         with:
           go-version: ${{ matrix.go }}
-      - name: Check out source
-        uses: actions/checkout@c85c95e3d7251135ab7dc9ce3241c5835cc595a9 # v3.5.3
       - name: Use test and module cache
         uses: actions/cache@88522ab9f39a2ea568f7027eddc7d8d8bc9d59c8 # v3.3.1
         with: