Eliminate transient container deps from wslkerninst

Resolves Win Installer CI issues where dep processing variance can
pull in gpgme, which doesn't compile on Windows without a
specialized msys2 setup.

Signed-off-by: Jason T. Greene <jason.greene@redhat.com>

pkg/machine/wsl/wutil/wutil.go

@@ -0,0 +1,55 @@
+//go:build windows
+// +build windows
+
+package wutil
+
+import (
+	"bufio"
+	"os/exec"
+	"strings"
+	"syscall"
+
+	"golang.org/x/text/encoding/unicode"
+	"golang.org/x/text/transform"
+)
+
+func SilentExec(command string, args ...string) error {
+	cmd := exec.Command(command, args...)
+	cmd.SysProcAttr = &syscall.SysProcAttr{CreationFlags: 0x08000000}
+	cmd.Stdout = nil
+	cmd.Stderr = nil
+	return cmd.Run()
+}
+
+func SilentExecCmd(command string, args ...string) *exec.Cmd {
+	cmd := exec.Command(command, args...)
+	cmd.SysProcAttr = &syscall.SysProcAttr{CreationFlags: 0x08000000}
+	return cmd
+}
+
+func IsWSLInstalled() bool {
+	cmd := SilentExecCmd("wsl", "--status")
+	out, err := cmd.StdoutPipe()
+	cmd.Stderr = nil
+	if err != nil {
+		return false
+	}
+	if err = cmd.Start(); err != nil {
+		return false
+	}
+	scanner := bufio.NewScanner(transform.NewReader(out, unicode.UTF16(unicode.LittleEndian, unicode.UseBOM).NewDecoder()))
+	result := true
+	for scanner.Scan() {
+		line := scanner.Text()
+		// Windows 11 does not set an error exit code when a kernel is not avail
+		if strings.Contains(line, "kernel file is not found") {
+			result = false
+			break
+		}
+	}
+	if err := cmd.Wait(); !result || err != nil {
+		return false
+	}
+
+	return true
+}