sysutils/git-backup: not backing up new firewall rules

[zoechi]

Important notices

• I have read the contributing guidelines at https://github.com/opnsense/core/blob/master/CONTRIBUTING.md
• I am convinced that my issue is new after having checked both open and closed issues at https://github.com/opnsense/core/issues?q=is%3Aissue

Describe the bug

I just migrated legacy firewall rules to the new rules.
Git backup didn't produce a commit.
Clicking "Setup/Test Git" produced a new commit, but didn't include new rules and didn't remove legacy rules.

The commit diff only contains

<backup><git persisted_at="<new timestamp>">

<revision>
  <description>/diag_backup.php made changes</description>
  <time><changed timestamp></time>

To Reproduce

Steps to reproduce the behavior:

1. migrate legacy firewall rules
2. click "Setup/Test Git" in System > Configuration > Backups
3. check backup

Expected behavior

Configuration changes should invoke Git backup and Git backup should include the changes

Additional context

This issue could be related to #10289

Git backup worked flawlessy before. The last backup commit was 17h ago.
I updated OPNSense to 26.1.8. Before it was the latest version available yesterday.

When I diff backup files created with "Download configuration" from before and after the rules migration, lots of removal and addition of rules are shown.

Environment

OPNsense 26.1.8 (amd64).