Bump org.a2aproject.sdk:a2a-java-sdk-client

Bumps the minor-updates group with 1 update: [org.a2aproject.sdk:a2a-java-sdk-client](https://github.com/a2aproject/a2a-java).


Updates `org.a2aproject.sdk:a2a-java-sdk-client` from 1.3.2.Final to 1.4.0.Final
- [Release notes](https://github.com/a2aproject/a2a-java/releases)
- [Changelog](https://github.com/a2aproject/a2a-java/blob/main/RELEASE.md)
- [Commits](a2aproject/a2a-java@v1.3.2.Final...v1.4.0.Final)

---
updated-dependencies:
- dependency-name: org.a2aproject.sdk:a2a-java-sdk-client
  dependency-version: 1.4.0.Final
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: minor-updates
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

impl/pom.xml

@@ -17,7 +17,7 @@
         <version.com.cronutils>9.2.1</version.com.cronutils>
         <version.docker.java>3.7.1</version.docker.java>
         <version.org.graalvm.polyglot>25.4.4.1.1</version.org.graalvm.polyglot>
-        <version.org.a2aproject.sdk>1.3.2.Final</version.org.a2aproject.sdk>
+        <version.org.a2aproject.sdk>1.4.0.Final</version.org.a2aproject.sdk>
         <version.com.google.code.gson>2.14.0</version.com.google.code.gson>
     </properties>
     <dependencyManagement>