Add clade definitions for 24A and 24B

[joverlee521]

Description of proposed changes

Add new Nextstrain clades 24A and 24B, following up on https://github.com/nextstrain/ncov/pull/1103. See commits for details.

Checklist

• [x] Checks pass
• [x] [Test run]
  • [x] https://nextstrain.github.io/forecasts-viz/?dataset=https://data.nextstrain.org/files/workflows/forecasts-ncov/trial/add-24A-24B/gisaid/pango_lineages/global/mlr/latest_results.json
  • [x] https://nextstrain.github.io/forecasts-viz/?dataset=https://data.nextstrain.org/files/workflows/forecasts-ncov/trial/add-24A-24B/gisaid/nextstrain_clades/global/mlr/latest_results.json

[joverlee521]

Ah, right the test run completed successfully but the trial results does not include 24A/24B because they are not in the clade counts yet.

Will have to wait on the release of the new Nextclade dataset and full re-run of ncov-ingest to see these new clades come through.

[corneliusroemer]

There should be just a few new clade calls (not yet all as I forgot full run), enough to test, so I triggered test runs again. https://github.com/nextstrain/forecasts-ncov/actions/runs/8705257996

It's probably worth merging asap as the lack of new clades causes some issues, see Canada for example

[corneliusroemer]

Coloring works - we're just waiting for the updated data

[joverlee521]

Force-pushed to include changes to the viz app to update the pivot clade.

Merging now since today's ncov-ingest run will be a full re-run to include the new Nextstrain clades (Slack).