Bump org.apache.logging.log4j:log4j-core in /testrunner-gradle-plugin

Bumps org.apache.logging.log4j:log4j-core from 2.17.1 to 2.25.3.

---
updated-dependencies:
- dependency-name: org.apache.logging.log4j:log4j-core
  dependency-version: 2.25.3
  dependency-type: direct:production
...

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Author: dependabot[bot]

testrunner-gradle-plugin/pom.xml

@@ -14,7 +14,7 @@
 
     <properties>
         <gradle.version>6.0</gradle.version>
-        <log4j.version>2.17.1</log4j.version>
+        <log4j.version>2.25.3</log4j.version>
     </properties>
 
     <dependencies>