chore(deps): Non-AWS dependency updates (#11)

* Update logstash-logback-encoder to 7.4

* Fix Jackson dependency conflict

---------

Co-authored-by: gu-scala-steward-public-repos[bot] <108136057+gu-scala-steward-public-repos[bot]@users.noreply.github.com>
Co-authored-by: Kelvin Chappell <kelvin.chappell@theguardian.com>

build.sbt

@@ -15,8 +15,12 @@ lazy val root = (project in file("."))
       s"-J-Dlogs.home=/var/log/${packageName.value}",
     ),
     libraryDependencies ++= Seq(
-      "net.logstash.logback" % "logstash-logback-encoder" % "7.3",
+      "net.logstash.logback" % "logstash-logback-encoder" % "7.4",
       ("com.gu" %% "simple-configuration-ssm" % "1.6.4").cross(CrossVersion.for3Use2_13),
       "org.scalatestplus.play" %% "scalatestplus-play" % "7.0.1" % Test,
     ),
+    dependencyOverrides ++= Seq(
+      // To keep all Jackson dependencies on the same version
+      "com.fasterxml.jackson.module" %% "jackson-module-scala" % "2.15.2" % Runtime,
+    )
   )