chore(ci): remove banned Jekyll + JS/TS-only CodeQL workflows (#24)

This repo is OCaml/Rust/Tangle/EBNF + Lean proofs. CodeQL's matrix is
hardcoded to javascript-typescript (build-mode: none) which finalizes
with exit code 32 because no JS/TS source exists. Per the canonical
CodeQL cron cleanup pattern in standards#286, drop the workflow rather
than retarget to actions-only (which produces no useful findings here).

Jekyll workflows are banned estate-wide (no Jekyll — use casket-ssg).
This mirrors the quandledb removal in PRs #16 and #18.

Closes the schedule-only `Deploy Jekyll site to Pages` red checks,
the schedule-only CodeQL `analyze` red, and the per-PR CodeQL noise
on every Tangle PR.

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: hyperpolymath