Admin command to check status is broken

This does not work since the maas admin subcommand is removed.
```
while [ $(maas admin boot-resources is-importing | cat) == "true" ]; do sleep 10; done; echo "syncing finished"
```

Start by locating the GitHub Action step that runs the shown shell loop, then inspect the current MAAS CLI commands for an equivalent status check because the admin subcommand was removed. The work is done when the installation workflow can wait for boot-resource importing to finish without invoking the removed command.

Written by the indexing model from the issue text.