Support Puma key_password_command for SSL key decryption

Puma v6.3 will likely release a feature needed to support encrypted SSL keys:

• https://github.com/puma/puma/pull/3133

We should add configuration support in both Omnibus and Cloud Native GitLab for this.

This depends on the following merge requests:

• Upgrade to Puma v6.2.2 (gitlab!119135 - merged)
• Make it possible to run Puma v6 (gitlab-org/build/CNG!1382 - merged)
• Make it possible to run Puma v6 (!6854 - merged)
• Make it possible to run Puma v6 (gitlab!119137 - merged)

UPDATE: Puma v6.3.0 has been released today. We now need:

• GitLab Rails: Update Puma to v6.3.0 (gitlab!122200 - merged)
• Omnibus: Support Puma key_password_command for SSL key d... (!6932 - merged)
• Cloud Native GitLab: Add Puma config support for SSL key decryption (gitlab-org/build/CNG!1417 - merged)