Bump github.com/docker/docker

Bumps [github.com/docker/docker](https://github.com/docker/docker) from 20.10.6+incompatible to 20.10.7+incompatible.
- [Release notes](https://github.com/docker/docker/releases)
- [Changelog](https://github.com/moby/moby/blob/master/CHANGELOG.md)
- [Commits](https://github.com/docker/docker/compare/v20.10.6...v20.10.7)

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

Signed-off-by: dependabot[bot] <support@github.com>

vendor/github.com/docker/docker/pkg/archive/archive.go

@@ -402,10 +402,24 @@ func fillGo18FileTypeBits(mode int64, fi os.FileInfo) int64 {
 // ReadSecurityXattrToTarHeader reads security.capability xattr from filesystem
 // to a tar header
 func ReadSecurityXattrToTarHeader(path string, hdr *tar.Header) error {
+	const (
+		// Values based on linux/include/uapi/linux/capability.h
+		xattrCapsSz2    = 20
+		versionOffset   = 3
+		vfsCapRevision2 = 2
+		vfsCapRevision3 = 3
+	)
 	capability, _ := system.Lgetxattr(path, "security.capability")
 	if capability != nil {
+		length := len(capability)
+		if capability[versionOffset] == vfsCapRevision3 {
+			// Convert VFS_CAP_REVISION_3 to VFS_CAP_REVISION_2 as root UID makes no
+			// sense outside the user namespace the archive is built in.
+			capability[versionOffset] = vfsCapRevision2
+			length = xattrCapsSz2
+		}
 		hdr.Xattrs = make(map[string]string)
-		hdr.Xattrs["security.capability"] = string(capability)
+		hdr.Xattrs["security.capability"] = string(capability[:length])
 	}
 	return nil
 }