Revert "vendor: update x/crypto/ssh - to fix Windows password length issues fixes #3798"

This turned out to introduce a regression, not being able to press Enter.

See: #3888 and https://github.com/golang/go/issues/36609

This reverts commit 251cfc100e.

vendor/golang.org/x/crypto/ssh/terminal/terminal.go

@@ -947,10 +947,6 @@ func readPasswordLine(reader io.Reader) ([]byte, error) {
 		n, err := reader.Read(buf[:])
 		if n > 0 {
 			switch buf[0] {
-			case '\b':
-				if len(ret) > 0 {
-					ret = ret[:len(ret)-1]
-				}
 			case '\n':
 				return ret, nil
 			case '\r':