chore(deps): update all shiki dependencies to ^1.21.0 (#159)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

package.json

@@ -86,7 +86,7 @@
     "@mdit-vue/types": "^2.1.0",
     "@semantic-release/changelog": "^6.0.3",
     "@semantic-release/git": "^10.0.1",
-    "@shikijs/markdown-it": "^1.20.0",
+    "@shikijs/markdown-it": "^1.21.0",
     "@stylistic/stylelint-plugin": "^2.1.3",
     "@types/jsdom": "^21.1.7",
     "@types/markdown-it": "^14.1.2",
@@ -112,7 +112,7 @@
     "rollup-plugin-visualizer": "^5.12.0",
     "sass": "^1.79.4",
     "semantic-release": "^24.1.2",
-    "shiki": "^1.20.0",
+    "shiki": "^1.21.0",
     "stylelint": "^16.9.0",
     "stylelint-config-html": "^1.1.0",
     "stylelint-config-recommended-scss": "^14.1.0",