ci: set up Go for CodeQL autobuild (#12007)

The workflow relied on a Go toolchain preinstalled on the runner
image; self-hosted runners without setup-go fail at autobuild with
'go: executable file not found'.

.github/workflows/codeql.yml

@@ -25,6 +25,12 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1
 
+      - name: Set up Go
+        uses: actions/setup-go@v7
+        with:
+          go-version-file: 'go.mod'
+          cache: ${{ runner.environment == 'github-hosted' }}
+
       # Initializes the CodeQL tools for scanning.
       - name: Initialize CodeQL
         uses: github/codeql-action/init@v4.39.0