pgsql: doc: Fix incorrect UUID index entry in function documentation.

doc: Fix incorrect UUID index entry in function documentation.

Previously, the UUID functions documentation defined the "UUID" index entry
to link to the UUID data type page, even though that entry already exists there.
Instead, the UUID functions page should define its own index entry linking
to itself.

This commit updates the UUID index entry in the UUID functions documentation
to point to the correct section, improving navigation and avoiding duplication.

Back-patch to all supported versions.

Author: Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
Reviewed-by: Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com>
Reviewed-by: Daniel Gustafsson <daniel(at)yesql(dot)se>
Discussion: https://postgr.es/m/f33e0493-5773-4296-87c5-7ce459054cfe@oss.nttdata.com
Backpatch-through: 13

Branch
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REL_13_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/6c0b598acc98451f98cc8e4514a68b2d4644d520

Modified Files
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doc/src/sgml/func.sgml | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)