Bump log4j-core from 2.14.0 to 2.15.0 in /log4j2-ecs-layout (#152)

Bumps log4j-core from 2.14.0 to 2.15.0.

---
updated-dependencies:
- dependency-name: org.apache.logging.log4j:log4j-core
  dependency-type: direct:development
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

log4j2-ecs-layout/pom.xml

@@ -9,7 +9,7 @@
 
     <properties>
         <parent.base.dir>${project.basedir}/..</parent.base.dir>
-        <version.log4j>2.14.0</version.log4j>
+        <version.log4j>2.15.0</version.log4j>
     </properties>
 
     <artifactId>log4j2-ecs-layout</artifactId>