workflows/benchmark: fix golang setup

Signed-off-by: Stephan Renatus <stephan.renatus@gmail.com>

Author: srenatus

.github/workflows/benchmarks.yaml

@@ -16,13 +16,9 @@ jobs:
         uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           path: regal
-      - id: go_version
-        name: Read go version
-        run: echo "go_version=$(cat .go-version)" >> $GITHUB_OUTPUT
-        working-directory: regal
       - uses: actions/setup-go@44694675825211faa026b3c33043df3e48a5fa00 # v6.0.0
         with:
-          go-version: ${{ steps.go_version.outputs.go_version }}
+          go-version-file: regal/go.mod
           cache-dependency-path: regal/go.sum
       - name: gobenchdata publish
         run: go run go.bobheadxi.dev/gobenchdata@v1 action