Add Packit commit trigger job

[evgeni]

This PR adds a second Packit job that triggers on commits to the default branch.

The new job:

• Inherits configuration from the existing pull_request job using YAML anchors
• Triggers on commits to the default branch
• Builds in the @theforeman/develop COPR project
• Uses the same targets and configuration as PR builds

This enables automated COPR builds on commits, making it easier to test changes from the development branch.

🤖 Generated with Claude Code

[adamruzicka]

Thank you @evgeni !