[Marketing] Remove em dash in Argosy case study section (#13851)

Co-authored-by: Claude <noreply@anthropic.com>

Author: garyhtou

app/views/marketing/funders.html.erb

@@ -340,7 +340,7 @@
         <p class="mk-lead">
           Beyond handling grant distribution, administration, and compliance, HCB gives the
           Argosy Foundation something a year-end report never could: a real-time,
-          grant-by-grant view of where their funding goes and the impact it's creating — with
+          grant-by-grant view of where their funding goes and the impact it's creating, with
           less overhead, not more.
         </p>
         <ul class="mk-ticks">