While updating the Jenkins release instances to 2.440.2 in prod,
we observed the matrix-auth plugin update to a recent version
without us having added any change to `plugins.txt`. Version 3.2 of
the plugin had introduced breaking changes, which caused the
deployments in prod to fail with the following error:

```
No signature of method: permissions() is applicable [...]
```

Breaking change:
https://plugins.jenkins.io/matrix-auth/releases/#version_3.2

We don't know what caused the plugin update. The problem doesn't
reproduce in the scap3-dev environment when updating to 2.440.2 (i.e
the plugin stays at the version in `plugins.txt`)

Updating the plugin explicitly in `plugins.txt` and adapting the
Jenkins configuration should fix the issue

Bug: T361084