Add spring-security.xsd symlink

Closes gh-13131

buildSrc/src/main/groovy/io/spring/gradle/convention/SchemaZipPlugin.groovy

@@ -1,9 +1,9 @@
 package io.spring.gradle.convention
 
-import org.gradle.api.plugins.JavaPlugin
-import org.gradle.api.tasks.bundling.Zip
 import org.gradle.api.Plugin
 import org.gradle.api.Project
+import org.gradle.api.plugins.JavaPlugin
+import org.gradle.api.tasks.bundling.Zip
 
 public class SchemaZipPlugin implements Plugin<Project> {
 
@@ -37,6 +37,15 @@ public class SchemaZipPlugin implements Plugin<Project> {
 						from xsdFile.path
 					}
 				}
+				File symlink = module.sourceSets.main.resources.find {
+					it.path.endsWith('org/springframework/security/config/spring-security.xsd')
+				}
+				if (symlink != null) {
+					schemaZip.into('security') {
+						duplicatesStrategy 'exclude'
+						from symlink.path
+					}
+				}
 			}
 		}
 	}

config/src/main/resources/org/springframework/security/config/spring-security.xsd

@@ -0,0 +1 @@
+spring-security-5.7.xsd

config/src/test/java/org/springframework/security/config/doc/XsdDocumentedTests.java

@@ -150,8 +150,8 @@ public class XsdDocumentedTests {
 				.getParentFile()
 				.list((dir, name) -> name.endsWith(".xsd"));
 		// @formatter:on
-		assertThat(schemas.length).isEqualTo(19)
-				.withFailMessage("the count is equal to 19, if not then schemaDocument needs updating");
+		assertThat(schemas.length).isEqualTo(20)
+				.withFailMessage("the count is equal to 20, if not then schemaDocument needs updating");
 	}
 
 	/**