fix: Temporary fix for Mermaid Gantt charts – hardcode width

closes #4594

shared/editor/plugins/Mermaid.ts

@@ -66,6 +66,12 @@ function getNewState({
             flowchart: {
               htmlLabels: false,
             },
+            // TODO: Make dynamic based on the width of the editor or remove in
+            // the future if Mermaid is able to handle this automatically.
+            gantt: {
+              // @ts-expect-error types do not include this property.
+              useWidth: 700,
+            },
             theme: pluginState.isDark ? "dark" : "default",
             fontFamily: "inherit",
           });