chore(deps): update actions/checkout action to v4

Author: renovate[bot]

.github/workflows/pr-auditor.yml

@@ -8,7 +8,7 @@ jobs:
   check-pr:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
         with:
           repository: 'sourcegraph/pr-auditor'
       - uses: actions/setup-go@v4

.github/workflows/update-tags.yml

@@ -11,7 +11,7 @@ jobs:
   dispatch:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
       - uses: actions/setup-go@v2
         with:
           go-version: "^1.18"