Remove root key mentions from the core YAML

[Neon-White]

Describe the Problem

In continuation to noobaa/noobaa-operator#1533 (which also contains a more elaborate explanation), this PR removes the references to the env var in the core YAMLs.

Issues:

Fixes:

1. DFBUGS-1608

Testing Instructions:

1. Deploy NooBaa
2. Perform some day 1 operations (bucket creation, bucket IO)

• Doc added/updated
• Tests added

[Copilot]

Copilot reviewed 4 out of 4 changed files in this pull request and generated no comments.

Comments suppressed due to low confidence (2)

src/test/unit_tests/test_encryption.js:906

• Verify that the removal of the subsequent load calls (previously used to reload the system state) does not leave the active root key state unvalidated. Consider adding explicit assertions to ensure that the state update is properly reflected after modifying the active root key file.

await fs.promises.writeFile(config.ROOT_KEY_MOUNT + '/active_root_key', 'key1');

src/server/system_services/master_key_manager.js:52

• Confirm that the revised get_root_key_id behavior (which now solely relies on this.active_root_key) correctly handles cases when active_root_key is undefined, since the environment variable fallback was removed.

return this.active_root_key && this.active_root_key.toString();