fix: auto-update poetry.lock (but not deps)

Fix —
```
0.870 Installing dependencies from lock file
0.910
0.910 pyproject.toml changed significantly since poetry.lock was last generated. Run `poetry lock [--no-update]` to fix the lock file.
------
failed to solve: process "/bin/sh -c poetry install --no-dev" did not complete successfully: exit code: 1
make: *** [build] Error 17
```
— via `poetry lock --no-update`.