Bumps the bincraft git-tag pin and version guard from v4.1.1 to v4.2.0 across
all .crow workflows, removes .crow/build-r-minor-sensitive-packages.yaml (now
superseded by the integrated full + iterative flow), and drops its now-orphaned
hook-exclude entries.
Split into two sequenced plans: bincraft 4.2.0 enhancements (per-minor index +
classifier-driven process_cran_updates) and the pipeline integration (full +
iterative). Spec revised to classify at the orchestration layer instead of a
build_binary_package "auto" mode.
Spec for integrating bincraft's ABI classifier (PR #49) into the iterative
and full build pipelines so only R-minor-sensitive packages are built per
installed R minor, leveraging the multi-R exec-env images.