fix(tests): Use unique S3 bucket name in bedrock evaluation system test

[ferruzzi]

Include env_id in the bucket name to prevent collisions when the test runs concurrently (e.g. local run + executor run). The hardcoded bucket name caused ValueError('The key ... already exists') when two executions overlapped.

---

Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)

---

• Read the Pull Request Guidelines for more information. Note: commit author/co-author name and email in commits become permanently public when merged.
• For fundamental code changes, an Airflow Improvement Proposal (AIP) is needed.
• When adding dependency, check compliance with the ASF 3rd Party License Policy.
• For significant user-facing changes create newsfragment: {pr_number}.significant.rst, in airflow-core/newsfragments. You can add this file in a follow-up commit after the PR is created so you know the PR number.

[ferruzzi]

This actually uncovered a buglett which is fixed in #68310. Three fields are listed as templated byut are not actually passed to templated_fields, which means the new bucket_name which has an embedded env_id wasn't resolving the env_id and passed the jinja template string un-rendered.