openvms: consider worker costly on OpenVMS
As for Windows, the parallel worker feature is less appealing on OpenVMS.
--- a/mercurial/worker.py Thu Aug 03 02:33:22 2023 +0200
+++ b/mercurial/worker.py Thu Aug 03 02:30:57 2023 +0200
@@ -61,7 +61,9 @@
return threading.current_thread() == threading.main_thread()
-if pycompat.isposix or pycompat.iswindows:
+if (
+ pycompat.isposix and pycompat.sysplatform != b'OpenVMS'
+) or pycompat.iswindows:
_STARTUP_COST = 0.01
# The Windows worker is thread based. If tasks are CPU bound, threads
# in the presence of the GIL result in excessive context switching and