Bump spring-expression from 4.1.5.RELEASE to 5.2.21.RELEASE in /train#21

dependabot[bot] wants to merge 1 commit intomasterJasonMHo/train:masterfrom

dependabot/maven/train/org.springframework-spring-expression-5.2.21.RELEASEJasonMHo/train:dependabot/maven/train/org.springframework-spring-expression-5.2.21.RELEASECopy head branch name to clipboard