Pin actions to a full length commit SHA (#14590)

- Pinned actions by SHA https://github.com/ossf/scorecard/blob/main/docs/checks.md#pinned-dependencies
- Included permissions for the action. https://github.com/ossf/scorecard/blob/main/docs/checks.md#token-permissions

https://docs.github.com/en/actions/security-guides/security-hardening-for-github-actions#using-third-party-actions

Also, dependabot supports upgrades based on SHA.

.github/workflows/go-cross.yml

@@ -11,6 +11,9 @@ concurrency:
   group: ${{ github.workflow }}-${{ github.head_ref }}
   cancel-in-progress: true
 
+permissions:
+  contents: read
+
 jobs:
   build:
     name: Build Tests with Go ${{ matrix.go-version }} on ${{ matrix.os }}
@@ -20,8 +23,8 @@ jobs:
         go-version: [1.17.x]
         os: [ubuntu-latest]
     steps:
-      - uses: actions/checkout@v2
-      - uses: actions/setup-go@v3
+      - uses: actions/checkout@629c2de402a417ea7690ca6ce3f33229e27606a5 # v2
+      - uses: actions/setup-go@bfdd3570ce990073878bf10f6b2d79082de49492 # v2
         with:
           go-version: ${{ matrix.go-version }}
           check-latest: true