Rudder

In 8.3 the upgrade of some dependencies should be done, indicative list from rudder parent project with mvn versions:display-dependency-updates :

[INFO]   ch.qos.logback:logback-classic ....................... 1.5.6 -> 1.5.12
[INFO]   ch.qos.logback:logback-core .......................... 1.5.6 -> 1.5.12
[INFO]   com.beachape:enumeratum_2.13 .......................... 1.7.4 -> 1.7.5
[INFO]   com.softwaremill.quicklens:quicklens_2.13 ............. 1.9.7 -> 1.9.9
[INFO]   commons-io:commons-io ............................... 2.16.1 -> 2.17.0
[INFO]   dev.zio:zio-concurrent_2.13 ......................... 2.0.22 -> 2.1.11
[INFO]   dev.zio:zio-interop-cats_2.13 ................... 23.1.0.2 -> 23.1.0.3
[INFO]   dev.zio:zio-json-yaml_2.13 ............................ 0.7.1 -> 0.7.3
[INFO]   dev.zio:zio-json_2.13 ................................. 0.7.1 -> 0.7.3
[INFO]   dev.zio:zio-stacktracer_2.13 ........................ 2.0.22 -> 2.1.11
[INFO]   dev.zio:zio-streams_2.13 ............................ 2.0.22 -> 2.1.11
[INFO]   dev.zio:zio-test-junit_2.13 ......................... 2.0.22 -> 2.1.11
[INFO]   dev.zio:zio-test_2.13 ............................... 2.0.22 -> 2.1.11
[INFO]   dev.zio:zio_2.13 .................................... 2.0.22 -> 2.1.11
[INFO]   io.scalaland:chimney_2.13 ............................. 1.4.0 -> 1.5.0
[INFO]   jakarta.servlet:jakarta.servlet-api ................... 5.0.0 -> 6.1.0
[INFO]   joda-time:joda-time ................................. 2.12.7 -> 2.13.0
[INFO]   org.slf4j:jcl-over-slf4j ...................... 2.0.13 -> 2.1.0-alpha1
[INFO]   org.specs2:specs2-core_2.13 ......................... 4.20.8 -> 4.20.9
[INFO]   org.specs2:specs2-junit_2.13 ........................ 4.20.8 -> 4.20.9
[INFO]   org.specs2:specs2-matcher-extra_2.13 ................ 4.20.8 -> 4.20.9
[INFO]   org.springframework:spring-expression ............... 6.1.12 -> 6.1.14
[INFO]   org.springframework:spring-tx ....................... 6.1.12 -> 6.1.14
[INFO]   org.springframework:spring-web ...................... 6.1.12 -> 6.1.14
[INFO]   org.springframework.security:spring-security-config ... 6.3.3 -> 6.3.4
[INFO]   org.springframework.security:spring-security-ldap ..... 6.3.3 -> 6.3.4
[INFO]   org.springframework.security:spring-security-web ...... 6.3.3 -> 6.3.4
[INFO]   org.tpolecat:doobie-specs2_2.13 ............... 1.0.0-RC5 -> 1.0.0-RC6
[INFO]   org.typelevel:cats-effect_2.13 .................. 3.5.4 -> 3.6-623178c
[INFO]   org.yaml:snakeyaml ........................................ 2.2 -> 2.3
[INFO] 
[INFO] The following dependencies in Plugin Dependencies have newer versions:
[INFO]   ch.epfl.scala:scala3-migrate-rules_2.13 ............... 0.6.2 -> 0.7.1
[INFO] 

Scala version (currently 2.13.12, updatable to 2.13.15) is done in PRs issues with Scala 3 (and compatibility with Scala 2 code).
ZIO 2.1 version is rather updated and tracked in #24968, it needs non-trivial changes