.github/workflows: upgrade all Actions versions

We update our other Actions to their respective latest versions:

  actions/checkout:           v1 -> v3
  actions/setup-go:           v2 -> v3

Author: chrisd8088

.github/workflows/ci.yml

@@ -9,8 +9,8 @@ jobs:
         go: ['1.18.x', '1.19.x']
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v1
-    - uses: actions/setup-go@v1
+    - uses: actions/checkout@v3
+    - uses: actions/setup-go@v3
       with:
         go-version: ${{ matrix.go }}
     - run: script/cibuild