feat: add fluidstack-ironwood DIB element and matrix workflow build

[nacef3005]

Adds first-class IPA ramdisk support for Ironwood TPU machines alongside the existing fish cluster build.

dib/fluidstack-ironwood — new DIB element

The element bundles everything IPA needs to provision Ironwood TPU machines:

• Network fixes — 10-bmc-usb.network suppresses the spurious IPv6 default route advertised by the BMC USB NIC (enp0s20f0u8*), which would otherwise steal source-address selection away from the DCN NIC and break IPA-to-Ironic connectivity. 10-dcn-ironwood.network pre-sets MTU 9100 on idpf interfaces before systemd-networkd processes the RA MTU option, avoiding the Failed to set IPv6 MTU error at boot.
• SSH over IPv6 — ssh.socket.d/ipv6.conf extends the Debian ssh.socket to listen on [::]:22; Ironwood DCN interfaces are IPv6-only so SSH is otherwise unreachable.
• hwclock wrapper — Ironwood BMCs expose no hardware RTC over the USB management interface; the wrapper prevents a hwclock --systohc failure during IPA teardown from aborting provisioning.
• IronwoodHardwareManager — a custom IPA hardware manager that adds a kexec_boot deploy step. After image deployment it kexecs directly into the installed OS, bypassing LinuxBoot's Verified Disk Boot (which requires LUKS encryption and EEPROM unlock on Ironwood machines).
• ironwood-auto-kexec service — a systemd oneshot that runs at IPA boot before ironic-python-agent.service. If the Ironic node is already in active state (already provisioned), it kexecs into the installed OS immediately, avoiding a full re-provisioning cycle on every reboot. Supports both a separate BOOT-labelled partition (Ubuntu cloud images) and /boot/ inside the root partition (DIB-built images).
• kexec-tools package — required by both the service and the hardware manager.

.github/workflows/ipa-ramdisk-build.yml — matrix build

The workflow is restructured as a matrix job so both images build in parallel on every push to main:

Variant Distro Release Image name

fish CentOS 9-stream ipa-centos9-<branch>-fs
ironwood Debian trixie ipa-debian-trixie-<branch>-fs

Per-variant elements (fluidstack-ironwood for ironwood, none for fisTRA_ELEMENTS env var so the shell loop handles the empty-string casecleanly. The fish build no longer includes --element fluidstack-ironwood since those fixes are Ironwood-specific. Both archives are uploaded to the same S3 prefix; the filename differentiates them.

[nacef3005]

• feat: add fluidstack-gpu DIB element for GPU qualification IPA image #11
• feat: add fluidstack-ironwood DIB element and matrix workflow build #10 👈 (View in Graphite)
• main

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[nacef3005]

Merge activity

• Jun 10, 1:29 PM UTC: A user started a stack merge that includes this pull request via Graphite.
• Jun 10, 1:29 PM UTC: @nacef3005 merged this pull request with Graphite.