Modernize Maven dependencies and build

[derreisende77]

Summary

• update compatible runtime and test dependencies, including WireMock 3
• use Maven's CI-friendly revision and Java 21 release settings
• exclude test dependencies from packaged runtime libraries
• remove obsolete repository and unused Maven properties
• update dependency analysis tooling for Java 21

Verification

• mvn -q clean package -DskipTests
• mvn -q test
• mvn -q dependency:analyze
• 445 tests passed with no failures or errors