Bump com.icegreen:greenmail from 2.1.0-rc-1 to 2.1.0 (#9530)

Bumps [com.icegreen:greenmail](https://github.com/greenmail-mail-test/greenmail) from 2.1.0-rc-1 to 2.1.0.
- [Release notes](https://github.com/greenmail-mail-test/greenmail/releases)
- [Commits](greenmail-mail-test/greenmail@release-2.1.0-rc-1...release-2.1.0)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

Diff for: build.gradle

@@ -70,7 +70,7 @@ ext {
     derbyVersion = '10.16.1.1'
     ftpServerVersion = '1.2.0'
     graalvmVersion = '24.0.2'
-    greenmailVersion = '2.1.0-rc-1'
+    greenmailVersion = '2.1.0'
     groovyVersion = '4.0.23'
     hamcrestVersion = '2.2'
     hazelcastVersion = '5.4.0'