Codex/skip dependabot integration tests

[soe-relewise]

https://trello.com/c/mohcRXYf/21181-skip-integration-tests-in-dependabot-builds-for-the-java-sdk

Summary

• Mark tests inheriting from TestBase as integration tests because they require DATASET_ID and API_KEY.
• Keep credential-independent tests in the unit-test path.
• Run only tests outside the integration group for Dependabot-triggered builds.
• Continue running the full test suite and test reporter for human-authored branches.
• Upgrade actions/setup-java to v5.6.0 and dorny/test-reporter to v3.

Superseded Dependabot PRs

This PR includes the changes from #48 and #49, which were closed without merging:

• Bump actions/setup-java from 4 to 5.6.0 #48: upgrade actions/setup-java from v4 to v5.6.0.
• Bump dorny/test-reporter from 1 to 3 #49: upgrade dorny/test-reporter from v1 to v3.

Those Dependabot branches appeared to fail because the existing CI workflow ran credential-dependent integration tests. Dependabot-triggered workflows intentionally do not receive the repository's DATASET_ID and API_KEY, so the failures did not necessarily indicate incompatibilities in the upgraded actions.

The action upgrades were folded into this human-authored PR so they can be validated by the normal CI path, including the full integration suite with the existing repository secrets. This also avoids merging the CI fix first and then resolving overlapping workflow changes when applying the two dependency upgrades separately.

Security rationale

The integration credentials are a dataset ID and Master API key for real customer datasets. They are not made available to Dependabot. Dependabot builds still generate and compile the SDK and run all tests that do not require those credentials.

Validation

• git diff --check passed.
• All workflow action references were audited after the upgrades.
• Maven was unavailable locally, so runtime validation is delegated to this human-authored GitHub Actions build.
• No generated SDK code was changed.

[mzanoni]

Can we allow dependabot to get the secrets instead of this workaround?