chore: update CODEOWNERS to change model to service

Author: rsynek

.github/CODEOWNERS

@@ -29,7 +29,7 @@ core/src/*/java/ai/timefold/solver/core/impl/solver/monitoring/** @triceo @Chris
 quarkus-integration/** @triceo @Christopher-Chianelli
 spring-integration/** @triceo @Christopher-Chianelli
 
-model/** @triceo @rsynek
+service/** @triceo @rsynek
 
 docs/** @triceo @TomCools
-**/*.adoc @triceo @TomCools
+**/*.adoc @triceo @TomCools