Fix release tests by checking QSTR function is registered (#113527) (#113575)

Author: carlosdelest

x-pack/plugin/esql/src/test/java/org/elasticsearch/xpack/esql/expression/function/fulltext/QueryStringFunctionTests.java

@@ -18,17 +18,24 @@
 import org.elasticsearch.xpack.esql.expression.function.FunctionName;
 import org.elasticsearch.xpack.esql.expression.function.TestCaseSupplier;
 import org.hamcrest.Matcher;
+import org.junit.BeforeClass;
 
 import java.util.Arrays;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.function.Supplier;
 
+import static org.elasticsearch.xpack.esql.action.EsqlCapabilities.Cap.QSTR_FUNCTION;
 import static org.hamcrest.Matchers.equalTo;
 
 @FunctionName("qstr")
 public class QueryStringFunctionTests extends AbstractFunctionTestCase {
 
+    @BeforeClass
+    public static void checkFunctionEnabled() {
+        assumeTrue("QSTR capability should be enabled ", QSTR_FUNCTION.isEnabled());
+    }
+
     public QueryStringFunctionTests(@Name("TestCase") Supplier<TestCaseSupplier.TestCase> testCaseSupplier) {
         this.testCase = testCaseSupplier.get();
     }