pgsql: doc: Remove deprecated clauses from CREATE USER/GROUP syntax syn

doc: Remove deprecated clauses from CREATE USER/GROUP syntax synopsis.

The USER and IN GROUP clauses of CREATE ROLE are deprecated, and
commit 8e78f0a1 removed them from the CREATE ROLE syntax syntax
synopsis in the docs. However, previously CREATE USER and
CREATE GROUP docs still listed these clauses.

Since CREATE USER is equivalent to CREATE ROLE ... WITH LOGIN and
CREATE GROUP is equivalent to CREATE ROLE, their documented syntax
synopsis should match CREATE ROLE to avoid confusion.

Therefore this commit removes the deprecated USER and IN GROUP
clauses from the CREATE USER and CREATE GROUP syntax synopsis
in the docs.

Author: Japin Li <japinli(at)hotmail(dot)com>
Reviewed-by: wenhui qiu <qiuwenhuifx(at)gmail(dot)com>
Reviewed-by: Chao Li <li(dot)evan(dot)chao(at)gmail(dot)com>
Reviewed-by: Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
Discussion: https://postgr.es/m/MEAPR01MB3031C30E72EF16CFC08C8565B687A@MEAPR01MB3031.ausprd01.prod.outlook.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/1b795ef0329d64427f3e779e38c7c492c0a15e5d

Modified Files
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doc/src/sgml/ref/create_group.sgml | 2 --
doc/src/sgml/ref/create_user.sgml | 2 --
2 files changed, 4 deletions(-)