Remove ParseSignal from client

Signed-off-by: Maksym Pavlenko <pavlenko.maksym@gmail.com>

client/signals.go

@@ -81,12 +81,3 @@ func GetOCIStopSignal(ctx context.Context, image Image, defaultSignal string) (s
 
 	return config.StopSignal, nil
 }
-
-// ParseSignal parses a given string into a syscall.Signal
-// the rawSignal can be a string with "SIG" prefix,
-// or a signal number in string format.
-//
-// Deprecated: Use github.com/moby/sys/signal instead.
-func ParseSignal(rawSignal string) (syscall.Signal, error) {
-	return signal.ParseSignal(rawSignal)
-}