ci: bump action-translation to v0.12.4

- CJK–MyST spacing rule for zh-cn translations
- MyST target-label blank-line cleanup in document reconstruction

Author: mmcky

.github/workflows/review-translations.yml

@@ -17,7 +17,7 @@ jobs:
         with:
           fetch-depth: 2
 
-      - uses: QuantEcon/action-translation@v0.12.3
+      - uses: QuantEcon/action-translation@v0.12.4
         with:
           mode: review
           source-repo: QuantEcon/lecture-python-programming