Ports: Remove obsolete openssh password prompt patch

As of 8dd11ae, we have `/dev/tty`, which is used by openssh's built-in
read_passphrase function to access the TTY, making our patch
unnecessary.

Removing it also fixes a subtle issue: we did not handle the case of
stdout not being a TTY correctly, so prompts failed to show up when e.g.
the ssh process was being piped to. This made `git clone` not work when
the server's fingerprint was not already verified.

Ports/openssh/patches/reimplement_read_passphrase.patch

@@ -1,101 +0,0 @@
-81548c85897681d42968dd7ca228c6b128ac39f1 Reimplement read_passphrase as a C version of Core::get_password
-diff --git a/readpass.c b/readpass.c
-index 974d67f0..3496eebe 100644
---- a/readpass.c
-+++ b/readpass.c
-@@ -47,6 +47,10 @@
- #include "ssh.h"
- #include "uidswap.h"
- 
-+#ifdef __serenity__
-+#include <termios.h>
-+#endif
-+
- static char *
- ssh_askpass(char *askpass, const char *msg, const char *env_hint)
- {
-@@ -122,62 +126,35 @@ ssh_askpass(char *askpass, const char *msg, const char *env_hint)
- char *
- read_passphrase(const char *prompt, int flags)
- {
--	char cr = '\r', *askpass = NULL, *ret, buf[1024];
--	int rppflags, use_askpass = 0, ttyfd;
--	const char *askpass_hint = NULL;
-+	// Reimplementation of Core::get_password
-+	fwrite(prompt, sizeof(char), strlen(prompt), stdout);
-+	fflush(stdout);
-+
-+	struct termios original;
-+	tcgetattr(STDIN_FILENO, &original);
- 
--	rppflags = (flags & RP_ECHO) ? RPP_ECHO_ON : RPP_ECHO_OFF;
--	if (flags & RP_USE_ASKPASS)
--		use_askpass = 1;
--	else if (flags & RP_ALLOW_STDIN) {
--		if (!isatty(STDIN_FILENO)) {
--			debug("read_passphrase: stdin is not a tty");
--			use_askpass = 1;
--		}
--	} else {
--		rppflags |= RPP_REQUIRE_TTY;
--		ttyfd = open(_PATH_TTY, O_RDWR);
--		if (ttyfd >= 0) {
--			/*
--			 * If we're on a tty, ensure that show the prompt at
--			 * the beginning of the line. This will hopefully
--			 * clobber any password characters the user has
--			 * optimistically typed before echo is disabled.
--			 */
--			(void)write(ttyfd, &cr, 1);
--			close(ttyfd);
--		} else {
--			debug("read_passphrase: can't open %s: %s", _PATH_TTY,
--			    strerror(errno));
--			use_askpass = 1;
--		}
-+	struct termios no_echo = original;
-+	no_echo.c_lflag &= ~ECHO;
-+	if (tcsetattr(STDIN_FILENO, TCSAFLUSH, &no_echo) < 0) {
-+		perror("Failed to turn off echo for passphrase");
-+		exit(errno);
- 	}
- 
--	if ((flags & RP_USE_ASKPASS) && getenv("DISPLAY") == NULL)
--		return (flags & RP_ALLOW_EOF) ? NULL : xstrdup("");
-+	char* password = NULL;
-+	size_t n = 0;
- 
--	if (use_askpass && getenv("DISPLAY")) {
--		if (getenv(SSH_ASKPASS_ENV))
--			askpass = getenv(SSH_ASKPASS_ENV);
--		else
--			askpass = _PATH_SSH_ASKPASS_DEFAULT;
--		if ((flags & RP_ASK_PERMISSION) != 0)
--			askpass_hint = "confirm";
--		if ((ret = ssh_askpass(askpass, prompt, askpass_hint)) == NULL)
--			if (!(flags & RP_ALLOW_EOF))
--				return xstrdup("");
--		return ret;
-+	int ret = getline(&password, &n, stdin);
-+	tcsetattr(STDIN_FILENO, TCSAFLUSH, &original);
-+	putchar('\n');
-+	if (ret < 0) {
-+		perror("Failed to read passphrase");
-+		exit(errno);
- 	}
- 
--	if (readpassphrase(prompt, buf, sizeof buf, rppflags) == NULL) {
--		if (flags & RP_ALLOW_EOF)
--			return NULL;
--		return xstrdup("");
--	}
-+	// Bit of a dirty way of removing the newline in password
-+	password[strcspn(password, "\n")] = '\0';
- 
--	ret = xstrdup(buf);
--	explicit_bzero(buf, sizeof(buf));
--	return ret;
-+	return password;
- }
- 
- int