Speed up the integration tests

This change runs more shards, which are now noticeably quicker to start.

Refs #976, 5e2bf81, dc04b4f

.github/workflows/ci.yml

@@ -162,7 +162,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        shard: [1, 2, 3, 4, 5]
+        shard: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
 
     steps:
       - name: 'Checkout code'