feat: add support for parsing comma-separated list environment variables

[fnesveda]

We're planning to add a new environment variable, ACTOR_BUILD_TAGS, to the Actor runtime, which will contain the list of build tags of the currently running Actor build. The environment variable will be a comma-separated list, but I think it would be easier to work with if it was already parsed to an array in the Configuration instance.

This adds support for parsing comma-separated list environment variables to arrays. In the SDK, I'll then just override the COMMA_SEPARATED_LIST_VARS list to include the environment variable I want to have parsed.

[janbuchar]

Just my curiosity, but how will ACTOR_BUILD_TAGS be useful to Actor code?

[fnesveda]

@janbuchar It's being requested every now and then, last time here: https://apify.slack.com/archives/C010Q0FBYG3/p1730272256106699

I have a project including several Actors that have some mutual interaction and need to be developed and tested together as the changes usually affects all the implementations. I usually do testing builds for multiple actors with the same tag, and just a simple

await Actor.call('another-actor', input, { build: Actor.getEnv().buildTag })

would save a lot of code writing and rewriting back during testing and releasing to production.

[janbuchar]

@janbuchar It's being requested every now and then, last time here: https://apify.slack.com/archives/C010Q0FBYG3/p1730272256106699

I have a project including several Actors that have some mutual interaction and need to be developed and tested together as the changes usually affects all the implementations. I usually do testing builds for multiple actors with the same tag, and just a simple

await Actor.call('another-actor', input, { build: Actor.getEnv().buildTag })

would save a lot of code writing and rewriting back during testing and releasing to production.

Right, so they have a bunch of Actors that call each other and follow the same versioning. Makes sense, I guess. Thanks!

[janbuchar]

LGTM