🌸 Components: Card does not need a gap-y (#2148)

- #2110

If we enforce a gap at the card level, it makes it hard to format things
nicely in contexts where there should not be a gap between the header
and footer.

The `justify-between` is "enough" to ensure that the footer sticks to
the bottom of the card, and the `header` and `footer` both provide
padding.

So no need to set that intention + enforce it multiple places; and this
place seemed like the one that was least tailorable to the immediate
usage context.

app/components/card_component.html.erb

@@ -1,4 +1,4 @@
-<div <%==attributes(classes: "shadow gap-y-3 rounded-lg bg-white group-hover:bg-slate-50 flex flex-col justify-between") %>>
+<div <%==attributes(classes: "shadow rounded-lg bg-white group-hover:bg-slate-50 flex flex-col justify-between") %>>
  <% if header? %>
   <%= header%>
  <%- end %>