Bump org.assertj:assertj-core in /data-prepper-plugins/otel-trace-source

Bumps [org.assertj:assertj-core](https://github.com/assertj/assertj) from 3.27.3 to 3.27.6.
- [Release notes](https://github.com/assertj/assertj/releases)
- [Commits](assertj/assertj@assertj-build-3.27.3...assertj-build-3.27.6)

---
updated-dependencies:
- dependency-name: org.assertj:assertj-core
  dependency-version: 3.27.6
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

data-prepper-plugins/otel-trace-source/build.gradle

@@ -29,7 +29,7 @@ dependencies {
     implementation libs.commons.lang3
     implementation libs.bouncycastle.bcprov
     implementation libs.bouncycastle.bcpkix
-    testImplementation 'org.assertj:assertj-core:3.27.3'
+    testImplementation 'org.assertj:assertj-core:3.27.6'
     testImplementation testLibs.slf4j.simple
     testImplementation libs.commons.io
     testImplementation 'org.skyscreamer:jsonassert:1.5.3'