Refactor-v-html-markdown.vue

What does this MR do and why?

Replaces dangerous v-html with our safe directive v-safe-html
Closes - #241888 (closed) Remove v-html from app/assets/javascripts/notebook/cells/markdown.vue

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app/assets/javascripts/notebook/cells/markdown.vue

@@ -140,7 +140,7 @@ export default {
     prompt: Prompt,
   },
   directives: {
-    SafeHtml
+    SafeHtml,
   },
   inject: ['relativeRawPath'],
   props: {