fix(ci): run workflows on PRs to release-v1#1154

MilesCranmerBot wants to merge 4 commits intoMilesCranmer:release-v1MilesCranmer/PySR:release-v1from

MilesCranmerBot:bot/enable-ci-release-v1-prsMilesCranmerBot/PySR:bot/enable-ci-release-v1-prsCopy head branch name to clipboard