## Changes
The installer.Upgrade() processing did not install Python dependencies.
This resulted in errors such as:
```
ModuleNotFoundError: No module named 'databricks.labs.blueprint'
```
Any new dependencies are now installed during the upgrade process.
Resolves: databrickslabs/ucx#1276
## Tests
The TestUpgraderWorksForReleases test now checks to see if the upgrade
process resulted in the dependencies being installed.
---------
Signed-off-by: Jim.Idle <jimi@idle.ws>