Use Go version from the PR.

Author: sbruens

.github/workflows/bench.yml

@@ -27,7 +27,7 @@ jobs:
       - name: Set up Go
         uses: actions/setup-go@v4
         with:
-          go-version-file: '${{ github.workspace }}/go.mod'
+          go-version-file: '${{ github.workspace }}/new/go.mod'
 
       - name: Install dependencies
         run: go install golang.org/x/perf/cmd/benchstat@latest