Migrate lookup acceptance tests to Hiera 5 data providers

[silug]

Short description

PRs #384/#385 removed the deprecated data_binding_terminus and environment_data_provider settings and the metadata.json data_provider key, as accepted in the OpenVox 9 deprecation review. Two acceptance tests still configured environment and module data through those removed mechanisms and began failing on all platforms once 9.0.0 beta packages were built (acceptance-pipelines run 31098859281).

Migrate the fixtures the same way #385 migrated the in-repo spec fixtures:

• tests/lookup/lookup.rb: bind the environment and module data functions through hiera.yaml (version 5, v4_data_hash) at the environment root and module roots; drop the data_provider key from metadata.json.

• tests/parser_functions/puppet_lookup_cmd.rb: env2/env3 (function providers) get env-level hiera.yaml v5 with v4_data_hash: environment::data; env4 (none) gets an explicit empty hierarchy, since environments always have a data layer under Hiera 5; production/env1 keep their still-supported v4 env hiera.yaml. mod2/mod3 (function) get module hiera.yaml v5 with v4_data_hash; mod4 (none) loses its hiera.yaml entirely so the module layer is absent, preserving the not-found behavior the assertions expect. The inert environment_data_provider lines and all 20 metadata.json data_provider keys are removed. One --explain assertion is updated because the environment data provider section now always appears in explain output (previously absent under provider none).

Verified on a local beaker rig (single almalinux 9 primary running openvox-agent 9.0.0beta2 and openvox-server 9.0.0beta4, the versions from the failing pipeline run): both pipeline failures reproduced exactly with the pristine tests, and both tests pass with this change. All lookup value expectations are unchanged -- the loader picks the same function implementations the v4 providers did (ruby when both ruby and puppet-language exist, e.g. env2/mod2; puppet-language when only it exists, e.g. env3/mod3) and the v4_data_hash backend even preserves the Deprecated API function explain wording the test asserts.

Note for rerunning on persistent hosts: the puppet_lookup_cmd teardown removes node1/node2 SSL keys but not the CA-signed certs, so back-to-back runs against the same CA need a puppetserver ca clean first. Fresh pipeline VMs are unaffected.

Checklist

I have:

• read the CONTRIBUTING.md document
• read and accepted the Developer Certificate of Origin document and added a Signed-off-by annotation to each of my commits
• read and accepted the AI Policy document and added Generated-by or Assisted-by annotations to each of my commits created with the help of an AI agent
• tested this code
• included documentation (including possible behaviour changes)
• documented the code
• added or modified regression test(s)
• added or modified unit test(s)