ci: rework code metrics around membrowse (#3887)

ci: replace the linkermap metrics pipeline with membrowse

Upload size history for a pinned roster of boards rather than every
target: per-commit history is only continuous for a bounded set, and the
roster is chosen to cover every dcd/hcd driver. Its coverage is derived
from hw/bsp/family.json instead of hand-written driver lists, so it
cannot go stale against the build.

Build only the pinned boards in the GHA cmake leg — CircleCI already
builds every board of every family, so the first-board-of-family
fallback added nothing.