Test against OpenSearch 3

Author: stevebauman

.github/workflows/run-tests.yml

@@ -20,7 +20,7 @@ jobs:
       fail-fast: true
       matrix:
         os: [ubuntu-latest]
-        opensearch: [2.19.3]
+        opensearch: [2.19.3, 3.7.0]
         php: [8.4, 8.3, 8.2]
         include:
           - php: 8.4