[CI] Updates testing STACK_VERSION

Author: picandocodigo

.buildkite/pipeline.yml

@@ -39,11 +39,11 @@ steps:
           skip: true
         # Compatibility tests for 8.x:
         - with:
-            stack_version: "8.6-SNAPSHOT"
+            stack_version: "8.8-SNAPSHOT"
             suite: "free"
             ruby: "3.2"
         - with:
-            stack_version: "8.6-SNAPSHOT"
+            stack_version: "8.8-SNAPSHOT"
             suite: "platinum"
             ruby: "3.2"
     command: ./.buildkite/run-tests.sh

.github/workflows/7.17-8.x.yml

@@ -26,7 +26,7 @@ jobs:
         sudo sysctl -w vm.max_map_count=262144
     - uses: elastic/elastic-github-actions/elasticsearch@master
       with:
-        stack-version: 8.5-SNAPSHOT
+        stack-version: 8.8-SNAPSHOT
         security-enabled: false
     - uses: ruby/setup-ruby@v1
       with: