Specify python2 for dockerfiles for v1 actions

[minkimcello]

Motivation

https://github.com/thefrontside/interactors/actions/workflows/release.yml

Approach

• Deleted the v1 tag (we should be using v# for branches and v#.# for tags but I didn't know any better at the time) and pushed v1.8 (latest) to the v1 branch. Now if anything breaks, I can create fixes and create PRs against the new v1 branch.
• Updated the two dockerfiles that were installing python to install python2 instead.
• Built the two images locally successfully.

TODOs

• Update interactors #152 to try out the updated dockerfiles directly from this branch
• Once ☝️ works, we can merge this PR and do a manual release of v1.9 and then update all of our frontside projects that are using the old release action to use v1.9

[cowboyd]

Appears to work!