chore(deps): bump org.mariadb.jdbc:mariadb-java-client in /backend

Bumps [org.mariadb.jdbc:mariadb-java-client](https://github.com/mariadb-corporation/mariadb-connector-j) from 3.3.3 to 3.4.0.
- [Release notes](https://github.com/mariadb-corporation/mariadb-connector-j/releases)
- [Changelog](https://github.com/mariadb-corporation/mariadb-connector-j/blob/master/CHANGELOG.md)
- [Commits](mariadb-corporation/mariadb-connector-j@3.3.3...3.4.0)

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

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

backend/build.gradle

@@ -146,7 +146,7 @@ subprojects {
         implementation 'org.xerial:sqlite-jdbc:3.45.3.0'
         implementation 'com.h2database:h2:2.2.224'
         implementation 'org.postgresql:postgresql:42.7.3'
-        implementation 'org.mariadb.jdbc:mariadb-java-client:3.3.3'
+        implementation 'org.mariadb.jdbc:mariadb-java-client:3.4.0'
 
         implementation "io.ktor:ktor-client-core:$ktor_version"
         //Using Apache Engine Ktor engine, because it is at this time the only one that supports following redirects