pgsql: Re-enable autoruns for for cmd.exe on Windows

Re-enable autoruns for for cmd.exe on Windows

This acts as a revert of b83747a8a65b and 9886744a361b. As pointed out
by Noah, HEAD and REL_17_STABLE are in a weird state where the code
paths adding /D would limit the spawn of child processes, but we still
have code paths where the spawn of more than one child process would be
possible.

Let's remove these /D switches for now, to bring back the code into a
state consistent with how autorun is configured on a Windows host.

Reported-by: Noah Misch
Discussion: https://postgr.es/m/20240630021211.f3.nmisch@google.com
Backpatch-through: 17

Branch
------
REL_17_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/fa1a63dffcd7113d990b3a50d7e697c7852dc9c5

Modified Files
--------------
src/bin/pg_ctl/pg_ctl.c | 4 ++--
src/test/regress/pg_regress.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)