gh-102567: Add missing newline to --help-all (GH-136391)

Author: hugovk

Python/initconfig.c

@@ -312,7 +312,7 @@ The following implementation-specific options are available:\n\
 "-X gil=[0|1]: enable (1) or disable (0) the GIL; also PYTHON_GIL\n"
 #endif
 "\
--X importtime[=2]: show how long each import takes; use -X importtime=2 to\
+-X importtime[=2]: show how long each import takes; use -X importtime=2 to\n\
          log imports of already-loaded modules; also PYTHONPROFILEIMPORTTIME\n\
 -X int_max_str_digits=N: limit the size of int<->str conversions;\n\
          0 disables the limit; also PYTHONINTMAXSTRDIGITS\n\