BUG #17247: How to avoid crating multiple Foreign keys on same column on same table.

The following bug has been logged on the website:

Bug reference:      17247
Logged by:          bipsy Nair
Email address:      nbipin29@gmail.com
PostgreSQL version: 13.4
Operating system:   Any OS
Description:

Issue: Postgres engine allows multiple FK on same columns for a same
table.This cause duplication and unwanted use of space . If we accidentally
run a script multiple times it creates the FK mulitple times. 
Ran the following statement 3 times : to add a foreign key
ALTER TABLE admin.emp
ADD FOREIGN KEY (deptno) 
REFERENCES admin.dept (deptno)
ON DELETE NO ACTION;

I see 3 its created thrice . In Oracle this statement should fail. Is there
any way this restriction can be applied on PG. 
admin    emp_deptno_fkey    emp    deptno    admin    dept    deptno
admin    emp_deptno_fkey1    emp    deptno    admin    dept    deptno
admin    emp_deptno_fkey2    emp    deptno    admin    dept    deptno

Please advice.