pkg: two postgresql clients

[ml]

Hello,

1.
pkg upgrade show this result:

New packages to be INSTALLED:
        postgresql13-client: 13.7
        postgresql15-client: 15.b1_1

Installed packages to be UPGRADED:
        firefox: 103.0.1,2 -> 103.0.2,2
        nspr: 4.34 -> 4.34.1
        opencore-amr: 0.1.5 -> 0.1.6
        py39-psutil: 5.9.1_1 -> 5.9.1_2

There are two different PG clients. Is this correct?

2.
The command 
pkg install  firefox
New packages to be INSTALLED:
        postgresql15-client: 15.b1_1
Installed packages to be UPGRADED:
        firefox: 103.0.1,2 -> 103.0.2,2

PG is not a dependent package of firefox?

I use version:
postgres -V 
postgres (PostgreSQL) 14.1

Franz