Update buildkit version to speed up start time

[giggsoff]

- What I did

I checked and compared linuxkit-builder startup time for current and upstream versions of buildkit.

- How I did it

• I cleaned linuxkit-builder (buildkit) container with docker rm -f --volumes linuxkit-builder
• I filled the volume of linuxkit-builder (buildkit) with the artifacts from EVE-OS (make pkg/alpine pkg/acrn pkg/acrn-kernel pkg/fw pkg/pillar eve) to have lots of data inside (16G as du indicates).
• I stopped the linuxkit-builder builder using docker commands and start it again.
• I measured the time difference before starting of linuxkit-builder container and the line running server on /run/buildkit/buildkitd.sock in docker logs linuxkit-builder.

For current version I get about 20 seconds to start.
For upstream version I get about 3 seconds to start.

- Description for the changelog

Let's update buildkit version to include startup speed fix moby/buildkit@0bb8505

[deitch]

@giggsoff a minor nit, but can you update the comment to indicate what git commit of github.com/moby/buildkit this is? That will make it easier to track changes in the future.

[giggsoff]

@giggsoff a minor nit, but can you update the comment to indicate what git commit of github.com/moby/buildkit this is? That will make it easier to track changes in the future.

That information is inside commit message and PR description, do you want to see something in addition?

[deitch]

Yes, please; can you add it to the comment? That way someone looking at that line with the OCI image digest, and sees the comment above with the date and master, knows the git commit it relates to. It isn't that hard to trace it back, but let's make this easy for people.

[deitch]

Let CI run, shouldn't take overly long since the changes a few weeks back.