How to build custom E2B sandbox for OpenHands

E2B is an open-source secure cloud environment (sandbox) made for running AI-generated code and agents. E2B offers Python and JS/TS SDK to spawn and control these sandboxes.

Install the CLI with NPM.
```
npm install -g @e2b/cli@latest
```
Full CLI API is here.
Build the sandbox

e2b template build --dockerfile ./Dockerfile --name "openhands"