better-setup-deadcode

Pinned golang.org/x/tools/cmd/deadcode via go install (run it after better-setup-go).

- uses: https://git.madapes.com/actions/better-setup-go@v1
  with: { go-version: "1.27.0" }
- uses: https://git.madapes.com/actions/better-setup-deadcode@v1
  with: { version: "v0.52.0" }