fix: nightly release build failures

[Zhaosn]

Fix nightly release workflow failure & add libvpl LICENSE download

Description

This PR addresses the persistent failures in the nightly release workflow starting from the run linked below:
https://github.com/alvr-org/ALVR-nightly/actions/runs/20474199147
(Release nightly #1995: Scheduled, Dec 24, 2025, 7:47 AM GMT+8)

Key Changes

fix cargo about tool invocation errors.(in this pull request)

2026-02-26 0:20:30.5227682 +00:00:00 [ERROR] cargo-about should not redirect its output in powershell, please use the -o, --output-file option to redirect to a file to avoid powershell encoding issues

Download the LICENSE file for libvpl as part of the nightly release pipeline, resolving missing file-related workflow errors.(alvr-org/ALVR-nightly#14)

thread 'main' (5688) panicked at alvr\xtask\src\packaging.rs:59:10:
called `Result::unwrap()` on an `Err` value: failed to copy `D:\a\ALVR-nightly\ALVR-nightly\deps\windows/libvpl/alvr_build/share/vpl/licensing/license.txt` to `D:\a\ALVR-nightly\ALVR-nightly\build\alvr_launcher_windows\licenses\libvpl.txt`: The system cannot find the path specified. (os error 3)

Testing & Validation

After implementing these changes:

• The GitHub Actions workflow for nightly releases now executes successfully without failures.
• I have successfully installed and tested the modified build on a Pico Neo 3 device.
• Following the libvpl upgrade included in these changes, the macroblocking issue on my B580 graphics card has been resolved, and the application no longer crashes when using high presets.

Additional Notes

I’ve verified end-to-end functionality to ensure no regressions in core ALVR features.

Thank you for reviewing this PR! Please let me know if any additional adjustments or tests are needed to get this merged.

Best regards,
Zhaosn

[Zhaosn]

I’m not sure how to adjust the syntax to pass the check :(, but I’ve successfully generated releases in my forked repository! If anyone is interested in restoring the nightly build, I hope my work can be of any help. Feel free to check out the forked repo and use it as a reference :D!