fix(deps): update dependency @mdit/plugin-sub to v1.0.3

Author: renovate[bot]

packages/server/package.json

@@ -27,7 +27,7 @@
     "@mathjax/src": "^4.1.3",
     "@mdit/plugin-katex": "1.0.1",
     "@mdit/plugin-mathjax": "1.1.0",
-    "@mdit/plugin-sub": "1.0.2",
+    "@mdit/plugin-sub": "1.0.3",
     "@mdit/plugin-sup": "1.0.2",
     "akismet": "^2.0.7",
     "dompurify": "3.4.12",