feat(terraform): expose runner path as module output

[cbartz]

Applicable spec: N/A

Overview

Expose the configured GitHub path (org or repo) as a Terraform output at both the charm and product module levels.

Rationale

Consumers of the Terraform module need to make routing decisions based on which GitHub org or repo a self-hosted runner is registered to. The path config value was already passed through but not exposed as an output.

Juju Events Changes

None.

Module Changes

• terraform/charm/outputs.tf: Added path output using lookup(var.config, "path", "").
• terraform/product/outputs.tf: Added all_runner_paths output mapping each runner app name to its configured GitHub path.

Library Changes

None.

Checklist

• The charm style guide was applied.
• The contributing guide was applied.
• The changes are compliant with ISD054 - Managing Charm Complexity
• The documentation for charmhub is updated.
• The PR is tagged with appropriate label (urgent, trivial, complex).
• The changelog is updated with changes that affects the users of the charm.
• The application version number is updated in github-runner-manager/pyproject.toml.