ci: read go version from go.mod in rust smoke job

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.github/workflows/volume-server-integration-tests.yml

@@ -157,10 +157,10 @@ jobs:
       - name: Checkout code
         uses: actions/checkout@v6
 
-      - name: Set up Go ${{ env.GO_VERSION }}
+      - name: Set up Go
         uses: actions/setup-go@v6
         with:
-          go-version: ${{ env.GO_VERSION }}
+          go-version-file: 'go.mod'
 
       - name: Set up Rust toolchain
         uses: dtolnay/rust-toolchain@stable