test/hil: fold openocd_wch into openocd, verify per board, resolve firmware by flasher extension (#3804)

test/hil: one openocd flasher, per-board verify and firmware extension

The four WCH boards move to `openocd`, leaving one flasher for all.

`verify` is now a per-board opt-out, not dropped fleet-wide: WCH cannot read flash back
over the WCH-Link sdi transport; the other seven openocd boards can, and say so explicitly.

FLASHER_SUFFIX decides each flasher's extension once — find_firmware returns the full path
and the flashers pass it through, so a build with only the wrong artifact is skipped rather
than failed mid-flash. --skip-flash bypasses the filter.

rescue_openocd() power-on-resets a wedged RP2040/RP2350 via its Rescue DP from the flash
retry; the probe has no reset line.

Drops unused openocd_adi, stflash, wlink_rs and uniflash, parks the unstable ra6m5_ek, and
tests that every roster flasher name dispatches.

0 files changed, 0 insertions, 0 deletions