fix: issue where Ape tries starting geth-dev for custom networks w/o URIs

[antazoey]

What I did

i forgot to specify a URI for my custom network and nothing was in evmchains yet and i noticed Ape went ahead and tried starting a geth dev for me with this , and that wouldnt really work.

this PR makes it so Ape only uses default localhost URI if nothing is configured AND we are in a dev-net (local or fork).

How I did it

check .is_dev before using DEFAULT_SETTINGS

How to verify it

make a config like:

networks:
  custom:
    - name: mainnet
      chain_id: 109
      ecosystem: shibarium
      base_ecosystem_plugin: polygon
      default_provider: node

try launching geth

before it would try geth dev because it couldnt find any URI.
but now it fails because it knows you are not using a dev net and there is no Uri

Checklist

• All changes are completed
• New test cases have been added
• Documentation has been updated