Bump logback.version from 1.5.18 to 1.5.20

Bumps `logback.version` from 1.5.18 to 1.5.20.

Updates `ch.qos.logback:logback-core` from 1.5.18 to 1.5.20
- [Release notes](https://github.com/qos-ch/logback/releases)
- [Commits](qos-ch/logback@v_1.5.18...v_1.5.20)

Updates `ch.qos.logback:logback-classic` from 1.5.18 to 1.5.20
- [Release notes](https://github.com/qos-ch/logback/releases)
- [Commits](qos-ch/logback@v_1.5.18...v_1.5.20)

---
updated-dependencies:
- dependency-name: ch.qos.logback:logback-core
  dependency-version: 1.5.20
  dependency-type: direct:production
  update-type: version-update:semver-patch
- dependency-name: ch.qos.logback:logback-classic
  dependency-version: 1.5.20
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

pom.xml

@@ -41,7 +41,7 @@
         <kafka.version>3.9.0</kafka.version>
         <kafka.scala.version>2.13</kafka.scala.version>
         <kryo.version>5.6.2</kryo.version>
-        <logback.version>1.5.19</logback.version>
+        <logback.version>1.5.21</logback.version>
         <vavr.version>0.10.6</vavr.version>
         <zookeeper.version>3.9.2</zookeeper.version>
         <junit.platform.version>1.3.2</junit.platform.version>