framework/13-inch/intel-core-ultra-series1: revert #1358 (fix intel_vpu firmware error -2)

[nmouha]

Description of changes

This reverts #1358 (framework/13-inch/intel-core-ultra-series1: fix intel_vpu firmware error -2).

The firmware is now upstreamed to linux-firmware (https://web.git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/commit/?id=9b870dde196d030a6c8872e8965dd28a0146c990), so #1358 is no longer needed.

Right now, there is no impact to my proposed change (all this does is avoid downloading a file twice). However, it is better to use the upstreamed version in case the firmware gets updated in the future.

Things done

• [X] Tested the changes in your own NixOS Configuration
• [X] Tested the changes end-to-end by using your fork of nixos-hardware and importing it via <nixos-hardware> or Flake input