Update buildkit w/ customizable output colors, etc.

Signed-off-by: Sean P. Kane <spkane00@gmail.com>

vendor/github.com/moby/buildkit/util/progress/progressui/init.go

@@ -0,0 +1,37 @@
+package progressui
+
+import (
+	"os"
+	"runtime"
+
+	"github.com/morikuni/aec"
+)
+
+var colorRun aec.ANSI
+var colorCancel aec.ANSI
+var colorWarning aec.ANSI
+var colorError aec.ANSI
+
+func init() {
+	// As recommended on https://no-color.org/
+	if _, ok := os.LookupEnv("NO_COLOR"); ok {
+		// nil values will result in no ANSI color codes being emitted.
+		return
+	} else if runtime.GOOS == "windows" {
+		colorRun = termColorMap["cyan"]
+		colorCancel = termColorMap["yellow"]
+		colorWarning = termColorMap["yellow"]
+		colorError = termColorMap["red"]
+	} else {
+		colorRun = termColorMap["blue"]
+		colorCancel = termColorMap["yellow"]
+		colorWarning = termColorMap["yellow"]
+		colorError = termColorMap["red"]
+	}
+
+	// Loosely based on the standard set by Linux LS_COLORS.
+	if _, ok := os.LookupEnv("BUILDKIT_COLORS"); ok {
+		envColorString := os.Getenv("BUILDKIT_COLORS")
+		setUserDefinedTermColors(envColorString)
+	}
+}