Summary:
### Issue

The test fails with the following error log

```
ts4|pid5229|:26320 2024-11-04 16:07:49.195 UTC [5299] LOG:  invalid value for clientcert: "1"
ts4|pid5229|:26320 2024-11-04 16:07:49.195 UTC [5299] CONTEXT:  line 4 of configuration file "/tmp/yb_test.org.yb.pgsql.TestPgEncryption#testSslWithCustomAuth[1].20241104160734848323.5716895373/ts-127.0.0.180-26320-1730736468102/pg_data/ysql_hba.conf"
ts4|pid5229|:26320 2024-11-04 16:07:49.195 UTC [5299] FATAL:  could not load pg_hba.conf
```

**Reason:** clientcert=1 is not longer supported from pg12. See https://www.postgresql.org/docs/12/ssl-tcp.html for reference.

### Fix

Change `clientcert=1` to `clientcert=verify-ca`.
Jira: DB-13693

Test Plan: Jenkins: test regex: .*TestPgEncryption.testSslWithCustomAuth.*

Reviewers: smishra, telgersma

Reviewed By: telgersma

Subscribers: telgersma

Differential Revision: https://phorge.dev.yugabyte.com/D39699