refactor(ci): inline build steps, delete build-binary.sh

Replace build-binary.sh with discrete workflow steps: Build
mistralrs-server, Collect artifacts. Remove commented-out NCCL
check block.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CLAUDE.md

@@ -27,7 +27,6 @@ Defined in `flavours.yml`. Each flavour specifies a name, `cuda_home`, `cargo_fe
 - `rpm/mistralrs.spec` — RPM spec (binary-only package, no rebuild)
 - `rpm/systemd/mistralrs@.service` — templated systemd unit (`@BINARY@` and `@FLAVOUR@` are sed-replaced during rpmbuild)
 - `rpm/systemd/mistralrs@.conf.example` — example env file for instances
-- `script/build-binary.sh` — compiles mistralrs-server with cargo (requires `FLAVOUR_NAME`, `CUDA_HOME`, `CARGO_FEATURES`, `CUDA_COMPUTE_CAP`, `SRC_DIR` env vars)
 - `script/setup/` — one-time infra setup scripts (DNS, TLS cert, nginx, GPG) for `rpm.lair.cafe` on host `oolon`
 
 ## Commands