fix: decode postgres time without subsecond

[granddaifuku]

This resolves #2707

The cause of the issue

The issue is caused by Postgres.

Specifically, when we select 0:0:0.123 from Postgres, it properly returns 00:00:00.123.
However, in the case of selecting 0:0:0.0, it returns 00:00:00, removing after the .0.

This leads to the error Decode(ParseFromDescription(InvalidLiteral), because it does not match the Time format.

test=# select '0:0:0.0'::time;
   time
----------
 00:00:00
(1 row)

test=# select '0:0:0.123'::time;
     time
--------------
 00:00:00.123
(1 row)

To solve this, I implemented the same logic as datetime.