Clean up small instancetypes #240
Description
Is your feature request related to a problem? Please describe:
Some instancetype series provide very small sizes which might not be useable in real-world scenarios. For example the DPDK/RT preferences have fairly high requirements which cannot be satisfied by the smallest sizes in the related instancetype series.
In general we should check for instancetypes which cannot satisfy the requirements of any preference we provide.
Describe the solution you'd like:
Drop unuseable instancetypes.
Describe alternatives you've considered:
Keep unuseable instancetypes but with higher maintenance burden.
Additional context:
Add any other context or screenshots about the feature request here.