deps: update Go version and upgrade golang.org/x/tools to v0.39.0

What's Changed

• deps: update Go version and upgrade golang.org/x/tools to v0.39.0 by @KoheiMatsuno99 in #66

New Contributors

• @KoheiMatsuno99 made their first contribution in #66

Full Changelog: v2.11.0...v2.12.0