vendor: update buildkit to v0.18.0-rc1

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/github.com/moby/buildkit/util/testutil/integration/run.go

@@ -198,7 +198,7 @@ func Run(t *testing.T, testCases []Test, opt ...TestOpt) {
 						defer sandboxLimiter.Release(1)
 
 						ctx, cancel := context.WithCancelCause(ctx)
-						defer cancel(errors.WithStack(context.Canceled))
+						defer func() { cancel(errors.WithStack(context.Canceled)) }()
 
 						sb, closer, err := newSandbox(ctx, br, getMirror(), mv)
 						require.NoError(t, err)
@@ -427,7 +427,16 @@ func prepareValueMatrix(tc testConf) []matrixValue {
 
 // Skips tests on platform
 func SkipOnPlatform(t *testing.T, goos string) {
-	if runtime.GOOS == goos {
+	skip := false
+	// support for negation
+	if strings.HasPrefix(goos, "!") {
+		goos = strings.TrimPrefix(goos, "!")
+		skip = runtime.GOOS != goos
+	} else {
+		skip = runtime.GOOS == goos
+	}
+
+	if skip {
 		t.Skipf("Skipped on %s", goos)
 	}
 }