Bump github.com/moby/buildkit from 0.9.1 to 0.9.2 (#506)

Bumps [github.com/moby/buildkit](https://github.com/moby/buildkit) from 0.9.1 to 0.9.2.
- [Release notes](https://github.com/moby/buildkit/releases)
- [Commits](moby/buildkit@v0.9.1...v0.9.2)

---
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

@@ -22,7 +22,7 @@ require (
 	github.com/matcornic/hermes/v2 v2.1.0
 	github.com/matrix-org/gomatrix v0.0.0-20210324163249-be2af5ef2e16
 	github.com/microcosm-cc/bluemonday v1.0.16
-	github.com/moby/buildkit v0.9.1
+	github.com/moby/buildkit v0.9.2
 	github.com/nlopes/slack v0.6.0
 	github.com/opencontainers/go-digest v1.0.0
 	github.com/opencontainers/image-spec v1.0.2-0.20210819154149-5ad6f50d6283

go.sum

@@ -894,8 +894,8 @@ github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh
 github.com/mitchellh/mapstructure v1.3.1/go.mod h1:bFUtVrKA4DC2yAKiSyO/QUcy7e+RRV2QTWOzhPopBRo=
 github.com/mitchellh/osext v0.0.0-20151018003038-5e2d6d41470f/go.mod h1:OkQIRizQZAeMln+1tSwduZz7+Af5oFlKirV/MSYes2A=
 github.com/moby/buildkit v0.8.1/go.mod h1:/kyU1hKy/aYCuP39GZA9MaKioovHku57N6cqlKZIaiQ=
-github.com/moby/buildkit v0.9.1 h1:6noq8jvkaRs3OQGTIDf5U5Etkgq6zsPmQHGWi5yhh88=
-github.com/moby/buildkit v0.9.1/go.mod h1:oVZKk3TMm0MlDx7XxnlF0wKmcpyrzOs9GEp0VXKWFPk=
+github.com/moby/buildkit v0.9.2 h1:9vRUpmncxR/zR4MI5/3/q20y9CoOV1L9qoJlundbKjk=
+github.com/moby/buildkit v0.9.2/go.mod h1:oVZKk3TMm0MlDx7XxnlF0wKmcpyrzOs9GEp0VXKWFPk=
 github.com/moby/locker v1.0.1/go.mod h1:S7SDdo5zpBK84bzzVlKr2V0hz+7x9hWbYC/kq7oQppc=
 github.com/moby/spdystream v0.2.0/go.mod h1:f7i0iNDQJ059oMTcWxx8MA/zKFIuD/lY+0GqbN2Wy8c=
 github.com/moby/sys/mount v0.1.0/go.mod h1:FVQFLDRWwyBjDTBNQXDlWnSFREqOo3OKX9aqhmeoo74=