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_15_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/5be9f84fe37528515e2c92080ed0b73273ed813a

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