fix(a11y): Use empty alt tag for profile image

It's always besides text that is the actual username, making this alt text redundant.

app/views/profiles/_image.html.erb

@@ -1,6 +1,6 @@
 <% if user.profile_image.attached? %>
   <% begin %>
-    <%= image_tag rails_public_blob_url(user.profile_image.variant(quality: 95, resize_to_fill: [size, size]).processed), loading: "lazy", height: size, width: size, alt: user.username %>
+    <%= image_tag rails_public_blob_url(user.profile_image.variant(quality: 95, resize_to_fill: [size, size]).processed), loading: "lazy", height: size, width: size, alt: "" %>
   <% rescue %>
   <% end %>
 <% end %>