fix(deps): update dependency org.testcontainers:testcontainers-bom to v2 (#349)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

backend/build.gradle

@@ -34,7 +34,7 @@ dependencies {
 	testImplementation 'io.projectreactor:reactor-test' // Add this for StepVerifier
 
 	// Test containers
-	testImplementation platform('org.testcontainers:testcontainers-bom:1.21.4')
+	testImplementation platform('org.testcontainers:testcontainers-bom:2.0.4')
 	testImplementation 'org.testcontainers:junit-jupiter'
 	testImplementation 'org.testcontainers:mongodb'
 	// end::tests[]