dotenv integration unable to handle .env files with export lines

[euphemism]

Describe the bug

.env files with export prefixes on the lines do not get parsed and injected into the environment.

This is a pattern that people use so that they can simply run source on .env. I came across this while trying to onboard an existing project at work with devenv.

To reproduce

https://gist.github.com/euphemism/25e21226f39ce33ebef940736e2a4167

An empty line is printed instead of bar.

Version

devenv 1.0.5 (aarch64-darwin)