fix: EvmVersion from_str

[yash-atreya]

Currently, EvmVersion won't get deserialized for spuriousdragon and tangerinewhistle.

This can be reproduced using:

cast run 0x6b5ca68eb4c4b38690ec12ba9f85409b618759646e50ab53b28f9d67f74978fc --rpc-url=https://rpc.ankr.com/eth --evm-version spuriousDragon
Error: failed to extract foundry config:
foundry config error: Unknown evm version: spuriousdragon for key "default.evm_version" in RunArgs for setting `evm_version`

Solution:

Handle camel case and lowercase