[BUG] Fix restore of backups when plugins with modesl are used

[matmair]

Please verify that this bug has NOT been raised before.

• I checked and didn't find a similar issue

Describe the bug*

If plugins with AppMixin run within an instance, we might not be able to restore all the backed up information as there is a direct connection between database and available plugins. This is not reflected in the current backup / restore setup.

Steps to Reproduce

N/A

Expected behaviour

do a multi-step process like proposed in #11214 (comment)

Deployment Method

None

Version Information

InvenTree-Version: 1.2.0 dev
Django Version: 5.2.10
Commit Hash: d00d472
Commit Date: 2026-01-30
Commit Branch: null
Database: django.db.backends.postgresql
Debug-Mode: False
Deployed using Docker: True
Platform: Linux-5.15.0-100-generic-x86_64-with-glibc2.41
Installer: DOC
Active plugins: false

Try to reproduce on the demo site

I did not try to reproduce

Is the bug reproducible on the demo site?

Not reproducible

Relevant log output

[matmair]

also see #11214 (comment)

I think we just have to ensure that the correct plugins are enabled before updating.

So we may need to ensure that the data is re-imported in a correct sequence:

Run InvenTree table migrations
Import core InvenTree data
Load plugin configs (to ensure the plugins are enabled to allow generation of tables)
Re-run migrations (to create the plugin tables)
Import plugin data from the backup