Bump ch.qos.logback:logback-classic from 1.2.7 to 1.2.13 in /examples (#235)

Bumps [ch.qos.logback:logback-classic](https://github.com/qos-ch/logback) from 1.2.7 to 1.2.13.
- [Commits](qos-ch/logback@v_1.2.7...v_1.2.13)

---
updated-dependencies:
- dependency-name: ch.qos.logback:logback-classic
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Stephen Colebourne <scolebourne@joda.org>

Author: dependabot[bot]

examples/pom.xml

@@ -67,7 +67,7 @@
   <!-- ==================================================================== -->
   <properties>
     <!-- Version -->
-    <logback-classic.version>1.2.7</logback-classic.version>
+    <logback-classic.version>1.2.13</logback-classic.version>
     <!-- Properties for joda-beans-maven-plugin -->
     <!-- Lock in JDK config (not Guava) and stick with older version -->
     <joda.beans.version>2.8.3</joda.beans.version>