pgsql: doc: Fix incorrect synopsis for ALTER PUBLICATION ... DROP ...

doc: Fix incorrect synopsis for ALTER PUBLICATION ... DROP ...

The synopsis for the ALTER PUBLICATION ... DROP ... command incorrectly
implied that a column list and WHERE clause could be specified as part of
the publication object. However, these options are not allowed for
DROP operations, making the documentation misleading.

This commit corrects the synopsis  to clearly show only the valid forms
of publication objects.

Backpatched to v15, where the incorrect synopsis was introduced.

Author: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Fujii Masao <masao.fujii@gmail.com>
Discussion: https://postgr.es/m/CAHut+PsPu+47Q7b0o6h1r-qSt90U3zgbAHMHUag5o5E1Lo+=uw@mail.gmail.com
Backpatch-through: 15

Branch
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REL_15_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/74b26c8c290c81de00c134bf63e315a803f5c259

Modified Files
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doc/src/sgml/ref/alter_publication.sgml | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)