phylogenetic-fauna: Update for default builds with fauna data

I think the diff in this commit warrants maintaining separate
GH Action workflows for NCBI vs fauna data builds instead of trying to
shoehorn both into a single complicated GH Action workflow.

Uses AWS Batch runtime with cpus/memory according to the repo's README
instructions.¹

¹ <https://github.com/nextstrain/avian-flu/blob/4ae5e32af0f00b3120d040bfd0b527a4b2c51c09/README.md?plain=1#L14>

.github/workflows/phylogenetic-fauna.yaml

@@ -1,4 +1,4 @@
-name: Phylogenetic NCBI
+name: Phylogenetic Fauna
 
 defaults:
   run:
@@ -31,27 +31,26 @@ jobs:
     uses: nextstrain/.github/.github/workflows/pathogen-repo-build.yaml@master
     secrets: inherit
     with:
-      runtime: docker
+      runtime: aws-batch
       run: |
         declare -a config;
 
-        config+=(
-          s3_src="s3://nextstrain-data/files/workflows/avian-flu/h5n1"
-        );
-
         if [[ "$TRIAL_NAME" ]]; then
           config+=(
             deploy_url="s3://nextstrain-staging/avian-flu_trials_${TRIAL_NAME}_"
           )
         fi;
 
         nextstrain build \
+          --detach \
+          --no-download \
+          --cpus 16 \
+          --memory 28800mib \
           . \
             deploy_all \
-            --snakefile Snakefile.genome \
             --config "${config[@]}"
 
       env: |
         NEXTSTRAIN_DOCKER_IMAGE: ${{ inputs.image }}
         TRIAL_NAME: ${{ inputs.trial-name }}
-      artifact-name: phylogenetic-full-genome-build-output
+      artifact-name: phylogenetic-fauna-build-output