Update dependency org.openapi.generator to v7.18.0 (#3601)

(cherry picked from commit f474f73)

Author: solrbot

changelog/unreleased/PR#3601-update-org-openapi-generator.yml

@@ -0,0 +1,7 @@
+title: Update org.openapi.generator to v7.18.0
+type: dependency_update
+authors:
+- name: solrbot
+links:
+- name: PR#3601
+  url: https://github.com/apache/solr/pull/3601

gradle/libs.versions.toml

@@ -177,7 +177,7 @@ nodegradle-node = "7.1.0"
 # @keep Node JS version used in node.gradle (LTS)
 nodejs = "22.18.0"
 onnx = "1.23.0"
-openapi = "7.14.0"
+openapi = "7.18.0"
 openjdk-jmh = "1.37"
 opentelemetry = "1.56.0"
 opentelemetry-prometheus = "1.56.0-alpha"