ci(pr_test.yml): specify go-version instead of using 'stable'

Author: anthony-gomez-fastly

.github/workflows/pr_test.yml

@@ -22,7 +22,7 @@ jobs:
       - uses: actions/checkout@v5
       - uses: actions/setup-go@v5
         with:
-          go-version: stable
+          go-version: "1.24.2"
       - name: golangci-lint
         uses: golangci/golangci-lint-action@v8
         with: