Work around Thymeleaf's dependency on spring-security-bom:6.0.0-RC2

Closes gh-33348

Author: wilkinsona

build.gradle

@@ -26,8 +26,12 @@ allprojects {
 
 	repositories {
 		mavenCentral()
-		if (version.contains('-')) {
-			maven { url "https://repo.spring.io/milestone" }
+		maven {
+			url "https://repo.spring.io/milestone"
+			content {
+				// Thymeleaf uses 6.0.0-RC2 of Security's bom in its dependency management
+				includeModule("org.springframework.security", "spring-security-bom")
+			}
 		}
 		if (version.endsWith('-SNAPSHOT')) {
 			maven { url "https://repo.spring.io/snapshot" }