Remove Thymeleaf dependency management

Fixes: gh-6161

Author: rwinch

gradle/dependency-management.gradle

@@ -195,8 +195,7 @@ dependencyManagement {
 		dependency 'org.slf4j:slf4j-nop:1.7.25'
 		dependency 'org.sonatype.sisu.inject:cglib:2.2.1-v20090111'
 		dependency 'org.springframework.ldap:spring-ldap-core:2.3.2.RELEASE'
-		dependency 'org.thymeleaf:thymeleaf-spring5:3.0.10.RELEASE'
-		dependency 'org.thymeleaf:thymeleaf:3.0.9.RELEASE'
+		dependency 'org.thymeleaf:thymeleaf-spring5:3.0.11.RELEASE'
 		dependency 'org.unbescape:unbescape:1.1.5.RELEASE'
 		dependency 'org.w3c.css:sac:1.3'
 		dependency 'xalan:serializer:2.7.2'

samples/boot/helloworld/spring-security-samples-boot-helloworld.gradle

@@ -1,7 +1,5 @@
 apply plugin: 'io.spring.convention.spring-sample-boot'
 
-ext['thymeleaf.version'] = '3.0.9.RELEASE'
-
 dependencies {
 	compile project(':spring-security-config')
 	compile project(':spring-security-web')

samples/boot/insecure/spring-security-samples-boot-insecure.gradle

@@ -1,7 +1,5 @@
 apply plugin: 'io.spring.convention.spring-sample-boot'
 
-ext['thymeleaf.version'] = '3.0.9.RELEASE'
-
 dependencies {
 	compile 'org.springframework.boot:spring-boot-starter-thymeleaf'
 	compile 'org.springframework.boot:spring-boot-starter-web'

samples/boot/oauth2login-webflux/spring-security-samples-boot-oauth2login-webflux.gradle

@@ -1,7 +1,5 @@
 apply plugin: 'io.spring.convention.spring-sample-boot'
 
-ext['thymeleaf.version'] = '3.0.9.RELEASE'
-
 dependencies {
 	compile project(':spring-security-config')
 	compile project(':spring-security-oauth2-client')

samples/boot/oauth2login/spring-security-samples-boot-oauth2login.gradle

@@ -1,7 +1,5 @@
 apply plugin: 'io.spring.convention.spring-sample-boot'
 
-ext['thymeleaf.version'] = '3.0.9.RELEASE'
-
 dependencies {
 	compile project(':spring-security-config')
 	compile project(':spring-security-oauth2-client')

samples/boot/oauth2webclient/spring-security-samples-boot-oauth2webclient.gradle

@@ -1,7 +1,5 @@
 apply plugin: 'io.spring.convention.spring-sample-boot'
 
-ext['thymeleaf.version'] = '3.0.9.RELEASE'
-
 dependencies {
 	compile project(':spring-security-config')
 	compile project(':spring-security-oauth2-client')