fix(fleet): disable typescript/no-unnecessary-type-assertion

Cascaded from socket-wheelhouse. The type-aware pass builds
scripts/**/*.mts a DEFAULT program (no strict tsconfig discoverable
above scripts/), dropping noUncheckedIndexedAccess and false-flagging
the fleet-mandated cached-for-loop `arr[i]!` assertions as unnecessary
— reddening 🔎 Check on scripts/repo/stage-publish-cli-exe.mts and
scripts/repo/output-purls-shallow-score.mts.

Author: jdalton