Bump ch.qos.logback:logback-core in /test/fixtures/hdfs-fixture

Bumps [ch.qos.logback:logback-core](https://github.com/qos-ch/logback) from 1.5.3 to 1.5.6.
- [Commits](qos-ch/logback@v_1.5.3...v_1.5.6)

---
updated-dependencies:
- dependency-name: ch.qos.logback:logback-core
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

test/fixtures/hdfs-fixture/build.gradle

@@ -71,7 +71,7 @@ dependencies {
   api 'org.apache.zookeeper:zookeeper:3.9.2'
   api "org.apache.commons:commons-text:1.12.0"
   api "commons-net:commons-net:3.10.0"
-  api "ch.qos.logback:logback-core:1.5.3"
+  api "ch.qos.logback:logback-core:1.5.6"
   api "ch.qos.logback:logback-classic:1.2.13"
   api 'org.apache.kerby:kerb-admin:2.0.3'
   runtimeOnly "com.google.guava:guava:${versions.guava}"