Bump com.google.guava:guava from 32.1.3-jre to 33.0.0-jre in /backend

Bumps [com.google.guava:guava](https://github.com/google/guava) from 32.1.3-jre to 33.0.0-jre.
- [Release notes](https://github.com/google/guava/releases)
- [Commits](https://github.com/google/guava/commits)

---
updated-dependencies:
- dependency-name: com.google.guava:guava
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

backend/build.gradle.kts

@@ -228,7 +228,7 @@ dependencies {
     implementation("org.springframework.boot:spring-boot-autoconfigure")
     implementation("com.googlecode.owasp-java-html-sanitizer:owasp-java-html-sanitizer:20220608.1")
     // => CVE-2023-2976
-    implementation("com.google.guava:guava:32.1.3-jre")
+    implementation("com.google.guava:guava:33.0.0-jre")
     // Manually updating to 1.1.13 because parents already latest version (CVE-2023-34062)
     implementation("io.projectreactor.netty:reactor-netty-http:1.1.13")
     var flywayCore = "org.flywaydb:flyway-core:9.22.2"