Bump ch.qos.logback:logback-classic in /pitest-maven

Bumps [ch.qos.logback:logback-classic](https://github.com/qos-ch/logback) from 1.2.11 to 1.2.13.
- [Commits](qos-ch/logback@v_1.2.11...v_1.2.13)

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

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

pitest-maven/pom.xml

@@ -201,7 +201,7 @@
 		<dependency>
 		    <groupId>ch.qos.logback</groupId>
 		    <artifactId>logback-classic</artifactId>
-		    <version>1.2.11</version>
+		    <version>1.2.13</version>
 		    <scope>test</scope>
 		</dependency>
 		<dependency>