molpopgen/fwdpy11: Version 0.21.0

0.21.0 Breaking changes Refactor {class}fwdpy11.conditional_models.SimulationStatus as an enum. This change makes correct use much easier. PR {pr}1161. Issue {issue}934. Fixes {class}fwdpy11.conditional_models.ConditionalModelOutput now contains fields allowing one to distinguish if the tracked mutation is still present in {attr}fwdpy11.DiploidPopulation.mutations and/or {attr}fwdpy11.DiploidPopulation.fixations PR {pr}1163. Issue {issue}1160. New features {func}fwdpy11.DiploidPopulation.create_from_tskit is now able to restore individual metadata, populating {attr}fwdpy11.DiploidPopulation.diploid_metadata and {attr}fwdpy11.DiploidPopulation.ancient_sample_metadata. PR {pr}1157. Issue {issue}1130. CI changes Remove tests using conda environments. This removal was a pragmatic decision to speed up CI time. Test macOS/x86 using brew instead of conda Reduce number of work flows run for PRs into the dev branch. Several work flows are only needed when merging into main. Reduce number of work flows running upon push to main/dev. We now use branch protection, so in theory any changes merging have passed their CI requirements