GPU: give Metal a column in the tuning parameter table

[ktf]

Without one, GPUDefParametersDefaultsDevice.h falls through to
'#error GPU TYPE NOT SET' for GPUCA_GPUTYPE_METAL, which the .metal source
defines, so nothing under Definitions/ could be compiled for the backend at all.

The values are copied from OPENCL, the other portable backend with no
vendor-specific tuning, so Metal starts at WARP_SIZE 32 and
THREAD_COUNT_DEFAULT 256. Real numbers want measuring on a device once the
kernels run. The column is appended last, as the earlier ones were; the order
is cosmetic, since the generator keys off the architecture name.

detect_gpu_arch reports METAL alongside the others so the generator emits the
block. Every existing architecture comes out byte-identical; the generated
device header gains only the Metal block and the architecture comment.

[alibuild]

Error while checking build/O2/fullCI_slc9 for 10b5bd3 at 2026-10-08 22:58:

## sw/BUILD/o2codechecker-latest/log
100% tests passed, 0 tests failed out of 1


## sw/BUILD/ThePEG-latest/log
collect2: error: ld returned 1 exit status

Full log here.

[davidrohr]

fine with me.
Somehow I thought I already approved the "refuse deterministic mode on metal", but perhaps I forgot to press submit, no idea...
Obviously we'll need to change FindO2GPU.cmake in aldist first again.

[ktf]

i think i made some mistake with the update and introduced extra quotes. i will clean that up before merging.

[ktf]

Nevermind. It was simply the GUI on the phone which was showing as changed things which were not. Now the commit has also been updated with the version bump. Since we agreed this is fine, I am merging it.