RHEL 9 grub rules are misaligned with DISA

#### Description of problem:

The content is misaligned with an external (third party) content that targets the same policy - typically, this means that a system hardened by our content doesn't pass the scan by the external content.

The STIG and STIG with GUI profiles only include the BIOS version of the grub rules. The rules are skipped on UEFI systems.

#### Details:

This content is not aligned with content from DISA

The misalignment affects these profiles:

- STIG
- STIG with GUI

The misalignment affects these rules:

- STIG ID: RHEL-09-212010
- grub2_uefi_password
- grub2_uefi_admin_username
- grub2_password
- grub2_admin_username

#### Outcome:

- [ ] This project's content can be improved:
- [ ] Check needs to be improved.
- [ ] Remediation needs to be improved.
- [ ] The external content's check is faulty - the other party needs to be notified, they have work to do.

#### SCAP Security Guide Version: 0.1.77

#### External Content's Version: v2r4