build(deps): bump github.com/moby/buildkit from 0.12.0 to 0.12.1 (#1947)

Bumps [github.com/moby/buildkit](https://github.com/moby/buildkit) from 0.12.0 to 0.12.1.
- [Release notes](https://github.com/moby/buildkit/releases)
- [Commits](https://github.com/moby/buildkit/compare/v0.12.0...v0.12.1)

---
updated-dependencies:
- dependency-name: github.com/moby/buildkit
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

go.mod

@@ -19,7 +19,7 @@ require (
 	github.com/julienschmidt/httprouter v1.3.0
 	github.com/kballard/go-shellquote v0.0.0-20180428030007-95032a82bc51
 	github.com/mattn/go-isatty v0.0.19
-	github.com/moby/buildkit v0.12.0
+	github.com/moby/buildkit v0.12.1
 	github.com/moby/patternmatcher v0.5.0
 	github.com/opencontainers/image-spec v1.1.0-rc4
 	github.com/opencontainers/selinux v1.11.0