Fix CI workflow and remove duplicate method definitions

[mherman22]

Summary

• Update deprecated GitHub Actions that cause CI failures:
  • actions/checkout v2 → v4
  • actions/setup-java v1 → v4 (with temurin distribution)
  • actions/cache v2 → v4
  • stCarolas/setup-maven v4 → v5
  • Replace s4u/maven-settings-action with setup-java built-in Maven server config
• Remove duplicate getPatientList() method definitions in MpiClientService, MpiClientWorker, and MpiClientServiceImpl that cause Java compilation errors
• Fix parseFhirPatient() call signature in FhirMpiClientServiceImpl.getPatientList() — was passing 1 arg, method requires 2

Test plan

• CI workflow runs successfully on push/PR
• mvn package compiles and all tests pass

[mherman22]

CI failure is a pre-existing issue

The build fails because the github-packages Maven repository at https://maven.pkg.github.com/isanteplus/isanteplus-packages requires authentication, and the RELEASE_USERNAME / RELEASE_TOKEN secrets are not available for fork PRs.

This affects all fork PRs, not just this one — the everest-core:1.1.0 dependency can't be resolved without valid credentials.

The code compiles and all 21 tests pass locally:

Tests run: 21, Failures: 0, Errors: 0, Skipped: 0

To fix CI for fork PRs, the workflow could use GITHUB_TOKEN (automatically available) instead of custom secrets, or the isanteplus-packages registry could be made public.

[mherman22]

Folded into #60.