Bump value from 2.8.8 to 2.8.9-ea-1

Bumps [value](https://github.com/immutables/immutables) from 2.8.8 to 2.8.9-ea-1.
- [Release notes](https://github.com/immutables/immutables/releases)
- [Commits](https://github.com/immutables/immutables/commits)

---
updated-dependencies:
- dependency-name: org.immutables:value
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

build.gradle

@@ -23,7 +23,7 @@ buildscript {
 		cfJavaClientVersion = "5.6.0.RELEASE"
 		checkstyleVersion = "8.37"
 		commonsTextVersion = "1.9"
-		immutablesVersion = "2.8.8"
+		immutablesVersion = "2.8.9-ea-1"
 		openServiceBrokerVersion = "3.4.0"
 		pmdVersion = "6.29.0"
 		springBootVersion = "2.5.8"