Add dependency between rncToXsd and versionlessXsd

Since processResources is configured directly instead of via the source
set container, an explicit dependency task between rncToXsd and
versionlessXsd must be defined.

Issue gh-13845

config/spring-security-config.gradle

@@ -111,11 +111,6 @@ dependencies {
 	testRuntimeOnly 'org.hsqldb:hsqldb'
 }
 
-def versionlessXsd = project.tasks.create("versionlessXsd", CreateVersionlessXsdTask) {
-	inputFiles.from(project.sourceSets.main.resources)
-	versionlessXsdFile = project.layout.buildDirectory.file("versionlessXsd/spring-security.xsd")
-}
-
 def rncToXsd = tasks.named('rncToXsd', RncToXsd)
 rncToXsd.configure {
 	rncDir = file('src/main/resources/org/springframework/security/config/')
@@ -123,6 +118,11 @@ rncToXsd.configure {
 	xslFile = new File(rncDir, 'spring-security.xsl')
 }
 
+def versionlessXsd = tasks.register("versionlessXsd", CreateVersionlessXsdTask) {
+	inputFiles.from(rncToXsd.map { task -> project.fileTree(task.xsdDir) })
+	versionlessXsdFile = project.layout.buildDirectory.file("versionlessXsd/spring-security.xsd")
+}
+
 tasks.named('processResources', ProcessResources).configure {
 	from(versionlessXsd) {
 		into 'org/springframework/security/config/'