Bump jackson-databind from 2.12.3 to 2.12.6.1 in /tests/test-jex

Bumps [jackson-databind](https://github.com/FasterXML/jackson) from 2.12.3 to 2.12.6.1.
- [Release notes](https://github.com/FasterXML/jackson/releases)
- [Commits](https://github.com/FasterXML/jackson/commits)

---
updated-dependencies:
- dependency-name: com.fasterxml.jackson.core:jackson-databind
  dependency-type: direct:production
...

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

Author: dependabot[bot]

tests/test-jex/pom.xml

@@ -18,7 +18,7 @@
     <main.class>org.example.myapp.Main</main.class>
     <jex.version>2.0</jex.version>
     <swagger.version>2.0.8</swagger.version>
-    <jackson.version>2.12.3</jackson.version>
+    <jackson.version>2.12.6.1</jackson.version>
     <avaje-inject.version>8.3</avaje-inject.version>
     <avaje-http.version>1.13-SNAPSHOT</avaje-http.version>
   </properties>