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

Closes spring-projectsgh-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" }