vendor: update buildkit to 926935b5

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>
Upstream-commit: 68b270b97c3038f25ea2e7e8c344f55b79fb686a
Component: engine

Author: tonistiigi

components/engine/vendor.conf

@@ -26,8 +26,8 @@ github.com/imdario/mergo                            7c29201646fa3de8506f70121347
 golang.org/x/sync                                   e225da77a7e68af35c70ccbf71af2b83e6acac3c
 
 # buildkit
-github.com/moby/buildkit                            928f3b480d7460aacb401f68610058ffdb549aca
-github.com/tonistiigi/fsutil                        3d2716dd0a4d06ff854241c7e8b6f3f904e1719f
+github.com/moby/buildkit                            926935b590c94c3659ebcc49cf44da47c1a65ff6
+github.com/tonistiigi/fsutil                        0f039a052ca1da01626278199624b62aed9b3729
 github.com/grpc-ecosystem/grpc-opentracing          8e809c8a86450a29b90dcc9efbf062d0fe6d9746
 github.com/opentracing/opentracing-go               1361b9cd60be79c4c3a7fa9841b3c132e40066a7
 github.com/google/shlex                             6f45313302b9c56850fc17f99e40caebce98c716