fix: upgrade pgbouncer alpine base image to address CVE-2025-1094

[Dashing-Nelson]

What issues does your PR fix?

• fixes update PGBouncer image with latest alpine base image #917
• fixes security vulnerability CVE-2025-1094

What does your PR do?

This PR upgrades the PGBouncer Alpine base image from 3.19 to 3.20 to address CVE-2025-1094 security vulnerability. The changes include:

• Updated Dockerfile to use Alpine 3.20 in both builder and runtime stages
• Incremented patch version from 1.22.1 to 1.22.1-patch.1
• Added changelog entry documenting the security fix
• Verified the updated image builds successfully

Checklist

For all Pull Requests

• Commits are signed off
• Commits have semantic messages
• Documentation updated (CHANGELOG.md)
• Passes ct linting

For releasing ONLY

• Chart.yaml version bumped (VERSION file updated)
• CHANGELOG.md updated

[stale]

This issue has been automatically marked as stale because it has not had activity in 60 days.
It will be closed in 7 days if no further activity occurs.

Thank you for your contributions.

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