fix(vdo): compile against firmware-11 SDK 1.15.1 (VDO_ERROR_NO_VIDEO)

[fishloa]

Fixes #245.

VdoError::code_name() referenced vdo_sys::VDO_ERROR_NO_VIDEO, which the firmware-11 Native SDK (1.15.1) vdo headers don't define (it was added in a later SDK), so the vdo crate failed to build against that sysroot:

error[E0425]: cannot find value `VDO_ERROR_NO_VIDEO` in crate `vdo_sys`
   --> crates/vdo/src/lib.rs:148:32

The arm is diagnostic-only and the _ => "VDO_ERROR_UNKNOWN" catch-all already covers the code, so dropping it lets vdo compile against both the fw11 (1.15.1) and fw12 (12.1.0) SDK sysroots.

Verified end-to-end: with this change the crate cross-compiles under axisecp/acap-native-sdk:1.15.1-{aarch64,armv7hf}-ubuntu22.04 and a real ACAP app (on-camera LL-HLS via VDO) runs on an ARTPEC-6 / firmware-11.11 camera.

If you'd rather keep the label for fw12+ instead of dropping it, a cfg/build-probe gate would also work — happy to switch this PR to that approach.

I think we should find a way to compile conditionally with the error code because I don't think the bindings will be particularly useful if we reduce them to supporting only the greatest common denominator. I haven't thought much about exactly how to do this, so I'm happy to discuss options or just go with whatever you propose as long as it sounds reasonable (with the reservation that we may change it down the road if we come up with something that has tangible benefits). But I would like to use this as a starting point (feel free to challenge me if you disagree): We should support the latest minor/micro version within each major version of AXIS OS.

Changing the verdict to request changes to make the status of the PR clearer, see earlier comment for details.