Bump logback-classic from 1.2.8 to 1.2.9

Bumps logback-classic from 1.2.8 to 1.2.9.

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

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

Author: dependabot[bot]

pom.xml

@@ -292,7 +292,7 @@
     <dependency>
       <groupId>ch.qos.logback</groupId>
       <artifactId>logback-classic</artifactId>
-      <version>1.2.8</version>
+      <version>1.2.9</version>
       <scope>test</scope>
     </dependency>
     <!-- Hamcrest is only here to make Infinitest happy. Not really used in the project. -->