Made postgresql.tests.Tests.test_connect_pool less flakey by increasing timeout value.

[sarahboyce]

Trac ticket number

N/A

Branch description

Aims to address this flakey ci failure for postgresql.tests.Tests.test_connect_pool

psycopg_pool.PoolTimeout: couldn't get a connection after 0.10 sec

When not set, the default timeout value is 30 seconds.
During the development of the connection pool feature, testing locally 30 seconds was very slow and so I updated to 0.1 seconds to get quick feedback on failures. This value might be too quick for the ci on occasions and hoping 5 seconds is a good compromise.

Checklist

• This PR targets the main branch.
• The commit message is written in past tense, mentions the ticket number, and ends with a period.

[nessita]

💯