Migrate rule policies to Rego v1

[dakshhhhh16]

Summary

This PR migrates the Rego policies in minder-rules-and-profiles to Rego v1 syntax as Phase 2 of the Rego v1 migration work from mindersec/minder#5262.
Child issue mindersec/minder#6463

It adds a reusable migration helper that extracts embedded YAML def: | policy blocks, runs opa fmt --v0-v1, and writes the formatted Rego back into place. The migration also updates docs/examples so downstream users have a repeatable path for their own rule type YAML.

What changed

• Added scripts/migrate-rego-v1.py and a task migrate-rego-v1 target.
• Migrated embedded Rego policies in rule types, security-baseline rule types, and autofill-insights rule types to import rego.v1.
• Removed future.keywords usage from policy docs and examples.
• Kept the migration script idempotent and whitespace-safe for YAML block scalars.

Validation

• python3 scripts/migrate-rego-v1.py --check .
• git diff --check
• go test ./...

Notes for reviewers

This should be a syntax-only migration. Any policy behavior change should be treated as unintended unless called out during review.

[dakshhhhh16]

@evankanderson
You can have a look into this. It will lead to close of issue #6463 and I can further start working on phase 3

[evankanderson]

I need to look into why the tests are failing in this repo.