Bump logback-classic from 1.3.6 to 1.3.8 (#673)

Author: dependabot[bot]

pom.xml

@@ -268,7 +268,7 @@
             <dependency>
                 <groupId>ch.qos.logback</groupId>
                 <artifactId>logback-classic</artifactId>
-                <version>1.3.6</version>
+                <version>1.3.8</version>
             </dependency>
             <!-- JUnit -->
             <dependency>