chore: Add Dockerfile.dev for local development

[kevaundray]

Issue Addressed

Currently whenever we build the Dockerfile file for local development using kurtosis , it recompiles everything on my laptop, even if no changes are made. This takes about 120 seconds on my laptop (might be faster on others).

Proposed Changes

Conservatively, I created a new Dockerfile.dev, so that the original file is kept the same, even though its pretty similar.

This uses --mount-type=cache saving the target and registry folder across builds.

Usage

docker build -f Dockerfile.dev -t lighthouse:dev .

Additional Info

• If you immediately redo the above command, it should have no effect, ie it shouldn't rebuild
• Modifying the cli crate gives about a 6x speedup from scratch, and modifying consensus gives about a 2x speedup

[kevaundray]

Note: the local_testnet kurtosis script has not been changed and still uses Dockerfile

[jimmygchen]

Thanks @kevaundray, I haven't had a chance to try it out, but this is great!