chore(deps): bump org.jetbrains.exposed:exposed-jdbc in /backend

Bumps [org.jetbrains.exposed:exposed-jdbc](https://github.com/JetBrains/Exposed) from 0.39.2 to 0.56.0.
- [Release notes](https://github.com/JetBrains/Exposed/releases)
- [Changelog](https://github.com/JetBrains/Exposed/blob/main/CHANGELOG.md)
- [Commits](JetBrains/Exposed@0.39.2...0.56.0)

---
updated-dependencies:
- dependency-name: org.jetbrains.exposed:exposed-jdbc
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

backend/build.gradle

@@ -138,7 +138,7 @@ subprojects {
         implementation("org.jsoup:jsoup:1.18.2")
 
         implementation("org.jetbrains.exposed:exposed-dao:0.39.2")
-        implementation("org.jetbrains.exposed:exposed-jdbc:0.39.2")
+        implementation("org.jetbrains.exposed:exposed-jdbc:0.56.0")
 
         implementation 'com.zaxxer:HikariCP:6.2.1'