doc: fix typo in flux-jobs(1)

Problem: flux-jobs(1) says there are three possible results, but
if we count COMPLETED, FAILED, CANCELED, and TIMEOUT, that's four!

Update the text to not depend on the number of results.

Fixes #5111

Author: chu11

doc/man1/flux-jobs.rst

@@ -162,7 +162,7 @@ states also exist: "pending", an alias for DEPEND,SCHED; "running", an
 alias for RUN,CLEANUP; "active", an alias for "pending,running".
 
 After a job has finished and is in the INACTIVE state, it can be
-marked with one of three possible results: COMPLETED, FAILED,
+marked with one of the possible results: COMPLETED, FAILED,
 CANCELED, TIMEOUT. Under the *result_abbrev* field name, these are
 abbreviated as CD, F, CA, and TO respectively.