Scale cell VMs
Scale cell VMs

We need to scale the cell VMs in order to satisfy ADR017[1].

Output from `make prod show-cf-memory-usage`:

```
Memory reserved by orgs: 1408000 MB (1375 GB)
Memory reserved by apps: 510380 MB (498.4 GB)

Total cell memory required to meet ADR017: 1056000 MB (1031.3 GB)
```

Current cell memory = 1006.5GB = 30.5 (r4.xlarge memory) * 33 (number of cell VMs in prod).

This means we are currently not satisfying ADR017. 36 instances is enough to
cover the current shortfall and respond to a recent request to increase an
organisation's quota.

[1] https://government-paas-team-manual.readthedocs.io/en/latest/architecture_decision_records/ADR017-cell-capacity-assignment/

alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf,alphagov/paas-cf