chore: take mystmd fork qe-v14 (mystmd 1.12.0)

.github/workflows/ci.yml

@@ -67,17 +67,17 @@ jobs:
       # engine a moving target between runs of the same lecture commit, which
       # makes failures impossible to bisect. Bumping it is deliberate.
       #
-      # This SHA is the fork's main as of 2026-09-10, `qe-v10`. It replaced
-      # 96ee78f5 (2026-06-12, `qe-v8`), which had fallen 40 commits behind, so
-      # the HTML build was running a materially older engine than
-      # build-ipynb.yml -- that workflow clones `main` and so tracks latest.
+      # This SHA is the fork's `qe-v14` tag (2026-11-04, mystmd 1.12.0). It
+      # replaced c1f274b8 (2026-09-10, just after `qe-v10`), which had fallen
+      # four tags behind, so the HTML build was again running an older engine
+      # than build-ipynb.yml -- that workflow clones `main` and so tracks latest.
       - name: Install mystmd (QuantEcon fork)
         run: |
           mkdir -p /tmp/qe-mystmd
           cd /tmp/qe-mystmd
           git init -q
           git remote add origin https://github.com/QuantEcon/mystmd.git
-          git fetch -q --depth 1 origin c1f274b8a27e150474bf2b70bd120627e1bb31ba
+          git fetch -q --depth 1 origin 8be13b7368c57a534d91a0513b7691e57bd591af
           git checkout -q FETCH_HEAD
           git rev-parse HEAD
           bun install