Update to spring-framework-bom:5.3.20

Closes gh-2086

Author: rwinch

gradle/dependency-management.gradle

@@ -3,7 +3,7 @@ dependencyManagement {
 		mavenBom 'io.projectreactor:reactor-bom:2020.0.19'
 		mavenBom 'com.fasterxml.jackson:jackson-bom:2.13.2.20220328'
 		mavenBom 'org.junit:junit-bom:5.8.2'
-		mavenBom 'org.springframework:spring-framework-bom:5.3.19'
+		mavenBom 'org.springframework:spring-framework-bom:5.3.20'
 		mavenBom 'org.springframework.data:spring-data-bom:2021.2.0-RC1'
 		mavenBom 'org.springframework.security:spring-security-bom:5.7.0-RC1'
 		mavenBom 'org.testcontainers:testcontainers-bom:1.17.1'