ci(build): bump FA4, quack and ffpa-attn (#3733)

* build: bump FA3/FA4 pin to pick up CuTe compile-key fixes

The pinned flash-attention ref 002cce0a1 (2026-07-03) predates both CuTe
compile-key fixes, so every forward/backward with a tensor max_seqlen --
i.e. every varlen/packed-sequence step -- rebuilt the compile key and
recompiled the kernel. Reported against a Qwen3.5-VL packed-sequence
finetune on B300.

Bump to ce088ab9ce0f (main), which adds over the old pin:

  - #2507 [CuTe, Bwd] fix backward compile key churn (max_seqlen tensor)
  - #2762 [CuTe, Fwd] stabilize tensor max_seqlen compile key
  - #2745 [CuTe] fix forward dynamic-shape correctness
  - #2819 [CuTe] speed up scalar SM100 mask compilation

#2798 raised the cute requirement to nvidia-cutlass-dsl>=4.6.2, so pin
the FA4 CUTLASS DSL install to 4.6.2 to match. Kept exact rather than
floating so the image stays reproducible.

Note this ref also feeds the FA3 (Hopper) wheel, which is built by
default, so the bump affects the default x86 image and not just
INSTALL_FA4=true builds.

Signed-off-by: Alexandros Koumparoulis <akoumparouli@nvidia.com>

* build: pin full flash-attention commit

Signed-off-by: Alexandros Koumparoulis <akoumparouli@nvidia.com>

* build: bump cutlass-dsl to 4.6.2, ffpa-attn to 0.2.3, quack-kernels to 0.6.4

flash_attn.cute (FA4) at the pinned FLASH_ATTN_REF builds against
nvidia-cutlass-dsl 4.6.2. quack-kernels and ffpa-attn both import the same
`cutlass` package, so all three have to agree on one version.

- quack-kernels 0.6.1 -> 0.6.4 (pins cutlass-dsl 4.6.2; 0.6.1 pinned 4.6.0)
- ffpa-attn 0.2.2 -> 0.2.3 (first release pinning cutlass-dsl 4.6.2 and
  quack-kernels 0.6.4; 0.2.2 hard-pinned 4.6.0/0.6.1)
- ffpa extra's explicit cutlass-dsl pin 4.6.0 -> 4.6.2

Because ffpa-attn 0.2.3 already declares the versions FA4 needs, the
resolution is conflict-free -- no override-dependencies entries required.
Corrects the apache-tvm-ffi note as well: FA4 declares
apache-tvm-ffi>=0.1.12 but never imports tvm-ffi, so the <=0.1.11 cap that
keeps tilelang working is not mutually exclusive with FA4.

Both lock files regenerated with uv 0.8.22 (the version CI pins); the diff
is confined to the six bumped packages.

Signed-off-by: Alexandros Koumparoulis <akoumparouli@nvidia.com>

* build: enable FA4 (INSTALL_FA4=true) by default

Flips the default in both stages that declare the ARG: wheel_builder (gates
building the flash_attn/cute wheel) and automodel_final (gates the
nvidia-cutlass-dsl[cu13] install and the flash_attn/cute symlink). Docker does
not inherit ARGs across stages, so flipping only the first would build the
wheel while skipping the DSL install and the symlink -- a half-installed FA4.

Both FA4 wheels are installed --no-deps, so flash-attn-4's declared
apache-tvm-ffi>=0.1.12 bound is never resolved and the <=0.1.11 cap that keeps
the tilelang kernels working still holds.

Signed-off-by: Alexandros Koumparoulis <akoumparouli@nvidia.com>

* build: correct the apache-tvm-ffi comment

The note claimed flash-attn-4 never imports tvm-ffi. That is wrong:
flash_attn/cute/cache_utils.py has a bare top-level `import tvm_ffi`, reached
eagerly through flash_attn.cute.__init__ -> interface.py, so importing
flash_attn.cute hard-requires it.

The cap itself is still right, but for a different reason. FA4 is installed
--no-deps, so its declared >=0.1.12 floor is never resolved, and the tvm_ffi
that is present comes via quack-kernels (>=0.1.6,<0.2) pinned here to 0.1.11.
FA4 therefore runs against an ffi older than it declares; the two symbols it
references, tvm_ffi.Function and tvm_ffi.__version__, both exist in 0.1.11.

Note this is unexercised: nothing selects attn_implementation="flash_attention_4"
until the FA4 backend lands, so flash_attn.cute is never imported by any test
here. Worth knowing given docker/Dockerfile sets
FLASH_ATTENTION_CUTE_DSL_CACHE_ENABLED=1, which turns on the AOT cache path in
that same cache_utils.py.

Verified against flash-attention ce088ab9, the pinned FLASH_ATTN_REF.
Comment only; no dependency or lock change.

Signed-off-by: Alexandros Koumparoulis <akoumparouli@nvidia.com>

---------

Signed-off-by: Alexandros Koumparoulis <akoumparouli@nvidia.com>