build(deps-dev): bump greenmail.version

Bumps `greenmail.version` from 2.1.0-alpha-1 to 2.1.0-alpha-2.

Updates `com.icegreen:greenmail-junit4` from 2.1.0-alpha-1 to 2.1.0-alpha-2
- [Release notes](https://github.com/greenmail-mail-test/greenmail/releases)
- [Commits](greenmail-mail-test/greenmail@release-2.1.0-alpha-1...release-2.1.0-alpha-2)

Updates `com.icegreen:greenmail` from 2.1.0-alpha-1 to 2.1.0-alpha-2
- [Release notes](https://github.com/greenmail-mail-test/greenmail/releases)
- [Commits](greenmail-mail-test/greenmail@release-2.1.0-alpha-1...release-2.1.0-alpha-2)

---
updated-dependencies:
- dependency-name: com.icegreen:greenmail-junit4
  dependency-type: direct:development
  update-type: version-update:semver-patch
- dependency-name: com.icegreen:greenmail
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

extensions/modules/mail/pom.xml

@@ -49,7 +49,7 @@
         <jakarta.mail-api.version>2.1.2</jakarta.mail-api.version>
         <eclipse.angus-mail.version>2.0.2</eclipse.angus-mail.version>
         <jakarta.activation-api.version>2.1.2</jakarta.activation-api.version>
-        <greenmail.version>2.1.0-alpha-1</greenmail.version>
+        <greenmail.version>2.1.0-alpha-2</greenmail.version>
     </properties>
 
     <dependencies>