Try to fix doc build error

Author: giampaolo

Doc/whatsnew/3.15.rst

@@ -744,8 +744,8 @@ subprocess
   process termination:
 
   - Linux ≥= 5.3 uses :func:`os.pidfd_open` + :func:`select.poll`
-  - macOS and other BSD variants use :func:`select.kqueue` + ``KQ_FILTER_PROC``
-    + ``KQ_NOTE_EXIT``
+  - macOS and other BSD variants use :func:`select.kqueue` +
+    ``KQ_FILTER_PROC`` + ``KQ_NOTE_EXIT``
   - Windows keeps using ``WaitForSingleObject`` (unchanged)
 
   If none of these mechanisms are available, the function falls back to the