chore(deps): update mysql docker tag to v8.4

Author: ibm-mend-app[bot]

.github/workflows/rspec-tests.yml

@@ -43,7 +43,7 @@ jobs:
 
     services:
       mysql:
-        image: mysql:8.2
+        image: mysql:8.4
         ports: ["3306:3306"]
         env:
           MYSQL_ROOT_PASSWORD: password