Bump ch.qos.logback:logback-core from 1.3.12 to 1.3.15 in /systemready

Bumps [ch.qos.logback:logback-core](https://github.com/qos-ch/logback) from 1.3.12 to 1.3.15.
- [Release notes](https://github.com/qos-ch/logback/releases)
- [Commits](qos-ch/logback@v_1.3.12...v_1.3.15)

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

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

Author: dependabot[bot]

systemready/pom.xml

@@ -214,7 +214,7 @@
         <dependency>
             <groupId>ch.qos.logback</groupId>
             <artifactId>logback-core</artifactId>
-            <version>1.3.12</version>
+            <version>1.3.15</version>
             <scope>test</scope>
         </dependency>