…missing `seccomp BPF program` in arm64 linux (#2665)

## Summary

The docker-image is failing to build in GHA:

https://github.com/jetify-com/devbox/actions/runs/16204700194/job/47358742840

The error indicates that the seccomp (secure computing mode) BPF
(Berkeley Packet Filter) program that Nix tries to load is incompatible
with the Docker container environment on ARM64.

When filter-syscalls = true (the default), Nix uses seccomp BPF to
filter system calls for security sandboxing. Setting filter-syscalls =
false disables Nix's syscall filtering, which bypasses the seccomp BPF
program entirely and prevents the error.

This PR uses the approach from #1811 to fix this for arm64 platforms.


## How was it tested?

`docker build --platform linux/arm64 -t devbox-image-arm64 -f
/Users/savil/code/jetpack/devbox/internal/devbox/generate/tmpl/DevboxImageDockerfile
.`
`docker build --platform linux/arm64 -t devbox-image-arm64 -f
/Users/savil/code/jetpack/devbox/internal/devbox/generate/tmpl/DevboxImageDockerfileRootUser
.`

BEFORE: these failed with the error seen in the GHA above
AFTER: build successfully

Also confirmed that --platform linux/amd64 would build successfully

## Community Contribution License

All community contributions in this pull request are licensed to the
project
maintainers under the terms of the
[Apache 2 License](https://www.apache.org/licenses/LICENSE-2.0).

By creating this pull request, I represent that I have the right to
license the
contributions to the project maintainers under the Apache 2 License as
stated in
the
[Community Contribution
License](https://github.com/jetify-com/opensource/blob/main/CONTRIBUTING.md#community-contribution-license).

## Summary

Fixes
https://github.com/jetify-com/devbox/actions/runs/16847493651/job/47729104601

This is a very specific fix to this job. I think a better solution is to
pass `--extra-access-tokens` flag into nix commands that may interact
with github.

## How was it tested?

Not sure how to test.

## Community Contribution License

All community contributions in this pull request are licensed to the
project
maintainers under the terms of the
[Apache 2 License](https://www.apache.org/licenses/LICENSE-2.0).

By creating this pull request, I represent that I have the right to
license the
contributions to the project maintainers under the Apache 2 License as
stated in
the
[Community Contribution
License](https://github.com/jetify-com/opensource/blob/main/CONTRIBUTING.md#community-contribution-license).

## Summary

Fixes #2668

## How was it tested?

## Community Contribution License

All community contributions in this pull request are licensed to the
project
maintainers under the terms of the
[Apache 2 License](https://www.apache.org/licenses/LICENSE-2.0).

By creating this pull request, I represent that I have the right to
license the
contributions to the project maintainers under the Apache 2 License as
stated in
the
[Community Contribution
License](https://github.com/jetify-com/opensource/blob/main/CONTRIBUTING.md#community-contribution-license).

## Summary

## How was it tested?

## Community Contribution License

All community contributions in this pull request are licensed to the
project
maintainers under the terms of the
[Apache 2 License](https://www.apache.org/licenses/LICENSE-2.0).

By creating this pull request, I represent that I have the right to
license the
contributions to the project maintainers under the Apache 2 License as
stated in
the
[Community Contribution
License](https://github.com/jetify-com/opensource/blob/main/CONTRIBUTING.md#community-contribution-license).