[CI] Updates 8.x stack version

Author: picandocodigo

.ci/test-matrix.yml

@@ -1,7 +1,7 @@
 ---
 STACK_VERSION:
   - 7.17-SNAPSHOT
-  - 8.3-SNAPSHOT
+  - 8.5-SNAPSHOT
 
 RUBY_TEST_VERSION:
 - 3.1
@@ -14,9 +14,9 @@ TEST_SUITE:
 - platinum
 
 exclude:
-  - STACK_VERSION: 8.3-SNAPSHOT
+  - STACK_VERSION: 8.5-SNAPSHOT
     RUBY_TEST_VERSION: 3.0
-  - STACK_VERSION: 8.3-SNAPSHOT
+  - STACK_VERSION: 8.5-SNAPSHOT
     RUBY_TEST_VERSION: 2.7
-  - STACK_VERSION: 8.3-SNAPSHOT
+  - STACK_VERSION: 8.5-SNAPSHOT
     RUBY_TEST_VERSION: 2.6