packages: add nvidia-dra-driver-gpu

[maherthomsi]

Description of changes:
Adds the nvidia-dra-driver-gpu package, which builds the NVIDIA GPU DRA driver (gpu-kubelet-plugin) and installs it as a host systemd service. The package is added to the bottlerocket-core-kit workspace and included in the kit manifest so it is available to consuming variants.

Bump settings sdk for this change to include bottlerocket-os/bottlerocket-settings-sdk#148

The DRA driver (nvidia-dra-driver-gpu.service) and the kubernetes device plugin (nvidia-k8s-device-plugin.service) both allocate the same GPUs, so only one runs at a time. This is enforced without a systemd Conflicts=: the DRA unit gates on ConditionFileNotEmpty=/etc/nvidia-dra-driver-gpu/enabled, and the marker is rendered run (non-empty) only when DRA is enabled and the device plugin is disabled. DRA is therefore opt-in and off by default.

Both settings present

kubelet-dra-drivers.nvidia.enabled	kubelet-device-plugins.nvidia.enabled	DRA service	device-plugin service	GPU publisher
enabled	disabled	running	off	DRA (ResourceSlice)
enabled	enabled	off (defers)	running	device plugin (nvidia.com/gpu)
disabled	enabled	off	running	device plugin
disabled	disabled	off	off	none

Settings extension not present (failure to adopt the DRA settings API)

Condition	DRA marker	DRA service	device-plugin service	GPU publisher
kubelet-dra-drivers extension absent	not rendered	off	running (its own default)	device plugin

What "unset" means per setting

Setting	If unset	Effect
kubelet-dra-drivers.nvidia.enabled	treated as disabled (default "false"; shipped default is false)	DRA off
kubelet-device-plugins.nvidia.enabled	treated as enabled (default "true"; classic behavior)	device plugin runs

Out-of-the-box default (both unset): DRA off, device plugin running.

Guarantees: exactly one GPU publisher at any time; the device plugin wins when both are enabled (deterministic, no boot-time race); with no settings API the DRA driver stays off

Testing done:

• Built the kits for x86_64 and aarch64
• Launched a custom ami with the driver added to the variant and ensured that the DRA driver was loaded.
• • Tested on aarch64
• • Tested on x86_64

Terms of contribution:

By submitting this pull request, I agree that this contribution is dual-licensed under the terms of both the Apache License, version 2.0, and the MIT license.

[maherthomsi]

Added settings-sdk changes to this PR

[maherthomsi]

Addresses review feedback on the nvidia-dra-driver-gpu package:

• spec: add Requires: %{_cross_os}nvidia-container-toolkit - the rendered unit invokes /usr/bin/nvidia-cdi-hook, which that package ships.
• service (base unit): replace the ExecStart=/usr/bin/false + Type=simple + Restart=always placeholder with an inert no-op (Type=oneshot, RemainAfterExit=true, ExecStart=/usr/bin/true). It no longer retries forever / logs to console before the drop-in renders, and the ExecStartPre checks are no longer duplicated between the base unit and the drop-in.
• exec-start-conf (drop-in): reference the optional settings.kubernetes.hostname-override only inside {{#if_not_null}}, so an unset value no longer fails the strict render. Move the daemon's Type=simple/Restart=always/RestartSec/RemainAfterExit=false into the enabled branch (previously inherited from the base) and drop the redundant {{else}} branch since the inert base now covers the disabled/unset case.