[CI] Adds 8.0.0-SNAPSHOT to test matrix

Author: picandocodigo

.ci/test-matrix.yml

@@ -1,6 +1,7 @@
 ---
 STACK_VERSION:
   - 7.16-SNAPSHOT
+  - 8.0.0-SNAPSHOT
 
 RUBY_TEST_VERSION:
 - 3.0
@@ -12,4 +13,10 @@ TEST_SUITE:
 - free
 - platinum
 
-exclude: ~
+exclude:
+  - STACK_VERSION: 8.0.0-SNAPSHOT
+    RUBY_TEST_VERSION: 2.7
+  - STACK_VERSION: 8.0.0-SNAPSHOT
+    RUBY_TEST_VERSION: 2.6
+  - STACK_VERSION: 8.0.0-SNAPSHOT
+    RUBY_TEST_VERSION: 2.5