Update plugin hmcts.ccd.sdk to v5.5.20 (#259)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

build.gradle

@@ -7,7 +7,7 @@ plugins {
   id 'io.spring.dependency-management' version '1.1.7'
   id 'org.springframework.boot' version '2.7.18'
   id 'com.github.kt3k.coveralls' version '2.12.2'
-  id 'hmcts.ccd.sdk' version '5.5.19'
+  id 'hmcts.ccd.sdk' version '5.5.20'
   id 'com.github.ben-manes.versions' version '0.51.0'
   id 'org.sonarqube' version '6.0.1.5171'
   id 'uk.gov.hmcts.java' version '0.12.66'