pgsql: Update executor documentation for run-time partition pruning

Update executor documentation for run-time partition pruning With run-time partition pruning, there is no longer necessarily an executor node for each corresponding plan node. Author: David Rowley Branch -- REL_11_STABLE Details --- https://git.postgresql.org/pg/commitdiff/fd5274a65b4f

pgsql: Update executor documentation for run-time partition pruning

Update executor documentation for run-time partition pruning With run-time partition pruning, there is no longer necessarily an executor node for each corresponding plan node. Author: David Rowley Branch -- master Details --- https://git.postgresql.org/pg/commitdiff/86a4819f691ba08bef0