Bump com.icegreen:greenmail in the development-dependencies group

Bumps the development-dependencies group with 1 update: [com.icegreen:greenmail](https://github.com/greenmail-mail-test/greenmail).


Updates `com.icegreen:greenmail` from 2.1.0 to 2.1.1
- [Release notes](https://github.com/greenmail-mail-test/greenmail/releases)
- [Commits](greenmail-mail-test/greenmail@release-2.1.0...release-2.1.1)

---
updated-dependencies:
- dependency-name: com.icegreen:greenmail
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: development-dependencies
...

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

build.gradle

@@ -69,7 +69,7 @@ ext {
     derbyVersion = '10.16.1.1'
     ftpServerVersion = '1.2.0'
     graalvmVersion = '23.0.6'
-    greenmailVersion = '2.1.0'
+    greenmailVersion = '2.1.1'
     groovyVersion = '4.0.24'
     hamcrestVersion = '2.2'
     hazelcastVersion = '5.3.8'