pgsql: Doc: remove stale entry for removed aclitem[] ~ aclitem operator

Doc: remove stale entry for removed aclitem[] ~ aclitem operator.

Commit 2f70fdb06 removed the deprecated containment operator
~(aclitem[],aclitem) from the catalogs, but missed removing its entry
from the documentation. (Arguably the blame should fall on c62dd80cd,
which added this entry in contravention of the longstanding policy
that we don't document deprecated aliases in the first place.)

Author: Shinya Kato <shinya11(dot)kato(at)gmail(dot)com>
Reviewed-by: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
Discussion: https://postgr.es/m/CAOzEurQSyR5psWukyhUz1LtxyO55C2Vfp0Fmt8w2jGKxhszQmQ@mail.gmail.com
Backpatch-through: 14

Branch
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REL_16_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/cbca4d3a83d914a079662e45bb861a3bfd2432c2

Modified Files
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doc/src/sgml/func.sgml | 14 --------------
1 file changed, 14 deletions(-)