Blank pentester access configuration while retaining pentester support paths

[Copilot]

This PR removes all currently active pentester access configuration from forms-deploy while keeping the existing pentester configuration model and code paths in place for future reuse. It effectively revokes pentester access by setting pentester config to empty defaults rather than deleting feature support.

• Scope

  • Removes/empties pentester-specific configuration introduced via prior staging updates (IP CIDRs, pentester email entries, and related access-config inputs).
  • Keeps Terraform/Ruby/HCL structures, variables, and validation logic intact.

• Configuration changes

  • Sets pentester config values to schema-valid empty values ([], {}, or "" as appropriate per field).
  • Applies this consistently in environment-specific config where pentester access was previously configured.

• What is intentionally unchanged

  • No removal of pentester feature plumbing (modules, variable definitions, or validation mechanisms).
  • No unrelated config or infrastructure behavior changes.

Example of the applied pattern:

# before
pentesters = {
  allowed_ips    = ["203.0.113.10/32", "203.0.113.11/32"]
  allowed_emails = ["pentester1@example.com", "pentester2@example.com"]
}

# after
pentesters = {
  allowed_ips    = []
  allowed_emails = []
}