Bump springVersion from 2.7.17 to 2.7.18

Bumps `springVersion` from 2.7.17 to 2.7.18.

Updates `org.springframework.boot:spring-boot-starter-web` from 2.7.17 to 2.7.18
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v2.7.17...v2.7.18)

Updates `org.springframework.boot:spring-boot-starter-thymeleaf` from 2.7.17 to 2.7.18
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v2.7.17...v2.7.18)

Updates `org.springframework.boot:spring-boot-starter-webflux` from 2.7.17 to 2.7.18
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v2.7.17...v2.7.18)

Updates `org.springframework.boot:spring-boot-starter-amqp` from 2.7.17 to 2.7.18
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v2.7.17...v2.7.18)

---
updated-dependencies:
- dependency-name: org.springframework.boot:spring-boot-starter-web
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.springframework.boot:spring-boot-starter-thymeleaf
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.springframework.boot:spring-boot-starter-webflux
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: org.springframework.boot:spring-boot-starter-amqp
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

build.gradle

@@ -23,7 +23,7 @@ group = 'io.pivotal.identityService'
 sourceCompatibility = '1.8'
 
 ext {
-	springVersion = '2.7.17'
+	springVersion = '2.7.18'
 	springSecurityVersion = '5.8.8'
 	cfEnvSsoVersion = '2.5.0'
 }