fix(ci): install server package via .ebextensions

Author: korikuzma

.ebextensions/01_download_data.config

@@ -24,3 +24,9 @@ container_commands:
     04_remove_seqrepo_zip:
         test: test -f "/usr/local/share/seqrepo.tar.gz"
         command: "rm /usr/local/share/seqrepo.tar.gz"
+
+    04_install_package:
+        leader_only: true
+        command: |
+            set -euo pipefail
+            pip install .