Replace fauna with curation pipeline

See commit messages for all the details. This PR removes our fauna-ingest pipeline, replacing it with a small ingest workflow which adds GenoFLU annotations to the metadata/sequences from our [seasonal-flu ingest workflow](https://github.com/nextstrain/seasonal-flu/tree/master/ingest). This layer uploads metadata/sequences to the canonical S3 locations, and thus the phylo workflows should run as normal. After merging, I'll update [the seasonal-flu upload workflow](https://github.com/nextstrain/seasonal-flu/blob/57144590f062ca17ca15c19b9a1102143162668b/.github/workflows/upload.yaml#L53-L67) as described there