Bump org.mariadb.jdbc:mariadb-java-client from 3.5.5 to 3.5.6 in /Plan (#4269)

Bumps [org.mariadb.jdbc:mariadb-java-client](https://github.com/mariadb-corporation/mariadb-connector-j) from 3.5.5 to 3.5.6.
- [Release notes](https://github.com/mariadb-corporation/mariadb-connector-j/releases)
- [Changelog](https://github.com/mariadb-corporation/mariadb-connector-j/blob/main/CHANGELOG.md)
- [Commits](mariadb-corporation/mariadb-connector-j@3.5.5...3.5.6)

---
updated-dependencies:
- dependency-name: org.mariadb.jdbc:mariadb-java-client
  dependency-version: 3.5.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Plan/build.gradle

@@ -75,7 +75,7 @@ subprojects {
         jetbrainsAnnotationsVersion = "26.0.2"
         jettyVersion = "11.0.26"
         mysqlVersion = "9.4.0"
-        mariadbVersion = "3.5.5"
+        mariadbVersion = "3.5.6"
         sqliteVersion = "3.42.0.1"
         adventureVersion = "4.24.0"
         hikariVersion = "7.0.2"