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 3.5.3 to 3.5.4.
- [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@3.5.3...3.5.4)

---
updated-dependencies:
- dependency-name: org.mariadb.jdbc:mariadb-java-client
  dependency-version: 3.5.4
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

backend/build.gradle

@@ -146,7 +146,7 @@ subprojects {
         implementation 'org.xerial:sqlite-jdbc:3.50.2.0'
         implementation 'com.h2database:h2:2.3.232'
         implementation 'org.postgresql:postgresql:42.7.7'
-        implementation 'org.mariadb.jdbc:mariadb-java-client:3.5.3'
+        implementation 'org.mariadb.jdbc:mariadb-java-client:3.5.4'
 
         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