Fix checkstyle failure with generated-sources (#1194)

Since https://github.com/hazelcast/hazelcast-mono/pull/1174, [checkstyle
is
failing](https://jenkins.hazelcast.com/job/Hazelcast-mono-EE-pr-nightly-tests/43/consoleText)
on files in `hazelcast/hazelcast-sql/target/generated-sources`.

Revert the removal of the suppression of warnings in
`generated-sources`.

GitOrigin-RevId: fb4ac71ddc2fa8c558c336b7ef8c4da867c5b89e

checkstyle/suppressions.xml

@@ -196,6 +196,9 @@
     <suppress checks="OperatorWrap" files="[\\/]src[\\/]test[\\/]java[\\/]com[\\/]hazelcast[\\/]jet[\\/]"/>
     <suppress checks="VisibilityModifier" files="[\\/]src[\\/]main[\\/]java[\\/]com[\\/]hazelcast[\\/]jet[\\/]impl[\\/]"/>
 
+    <suppress checks="" files="target[\\/]generated-sources"/>
+    <suppress checks="" files="target[\\/]generated-test-sources"/>
+
     <!-- Javadoc suppressions -->
     <suppress checks="JavadocPackage" files="com[\\/]hazelcast[\\/]security[\\/]"/>