[UPGRADE] Upgrade of PgBouncer [Kubernetes]

[erzetpe]

Is your feature request related to a problem? Please describe.
We need to upgrade PgBouncer if possible and needed to the newer version. This task should be done after we will upgrade PostgreSQL to v13.
This task applies to K8s application

Describe the solution you'd like
We want to upgrade if possible and needed to the newer version of PgBouncer.

Describe alternatives you've considered
None.

Additional context
This task should be done after upgrade of PostgreSQL to v13.

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DoD checklist

• Changelog updated
• COMPONENTS.md updated / doesn't need to be updated
• Feature has automated tests
• Automated tests passed (QA pipelines)
  • apply
  • upgrade
• Idempotency tested
• Documentation added / updated / doesn't need to be updated
• All conversations in PR resolved
• Solution meets requirements and is done according to design doc
• Usage compliant with license

[przemyslavic]

We are currently using PgBouncer v1.10.
As for now the latest available is v1.15.0.
Need to update OS packages and docker image for application deployment on kubernetes.

[atsikham]

Steps:

1. Fix installation (apply) of a new verion(there is Python3 dependency - create a new role to install).
2. Upgrade with taking into account notes here.
3. ARM support?

[plirglo]

This tasks basically includes two different tasks:

• Upgrade and configuration pgbouncer as a k8s instance
• Upgrade and configuration pgbouncer installed directly on database hosts as standalone application. In this case Python dependency is needed (blocked by [BACKPORT][0.9.3] The default values can't be changed in cluster config file for virtual machine. #2334). Created: #2453

This might be good to split this task up to two different ones.

[plirglo]

PR #2462

[przemyslavic]

✔️ New installations have been tested, as well as the upgrade from v1.12. I've also deployed a sample application on k8s with psql and connected/executed test queries via pgbouncer to postgresql without any problems.