pretty-print: drop extra ';' from progress reporting end sequence

This corrects the closing sequence for the ConEmu progress reporting
final sequence. We by mistake sent two final ;;, where only one was
expected. The terminals I tested this with didn't care, but Ghostty
apparently does. Let's fix things and generate the closing sequence as
per doc:

https://conemu.github.io/en/AnsiEscapeCodes.html#ConEmu_specific_OSC

src/shared/pretty-print.c

@@ -556,7 +556,7 @@ void clear_progress_bar_unbuffered(const char *prefix) {
                       stderr);
         else
                 /* Undo Windows Terminal progress indication again. */
-                fputs(ANSI_OSC "9;4;0;;" ANSI_ST
+                fputs(ANSI_OSC "9;4;0;" ANSI_ST
                       ANSI_ERASE_TO_END_OF_LINE, stderr);
 
         fputc('\r', stderr);