Update dependency org.junit:junit-bom to v5.13.0 (open-telemetry#84)

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

Author: renovate[bot]

buildSrc/src/main/kotlin/otel.java-conventions.gradle.kts

@@ -92,7 +92,7 @@ testing {
     dependencies {
       implementation(project(project.path))
 
-      implementation(enforcedPlatform("org.junit:junit-bom:5.12.2"))
+      implementation(enforcedPlatform("org.junit:junit-bom:5.13.0"))
       implementation(enforcedPlatform("org.assertj:assertj-bom:3.27.3"))
 
       implementation("org.junit.jupiter:junit-jupiter-api")