chore: typo - Collab.ts (#6812)

src/excalidraw-app/collab/Collab.tsx

@@ -333,7 +333,7 @@ class Collab extends PureComponent<Props, CollabState> {
      * Indicates whether to fetch files that are errored or pending and older
      * than 10 seconds.
      *
-     * Use this as a machanism to fetch files which may be ok but for some
+     * Use this as a mechanism to fetch files which may be ok but for some
      * reason their status was not updated correctly.
      */
     forceFetchFiles?: boolean;