Bug 41705: (follow-up) Hide receipt page buttons when printing

The Print receipt and Close buttons added in the previous patch use
class="no-print", but printreceiptinvoice.css had no @media print rule
for that class — so they appeared in the printed output (e.g. when
saving as PDF or auto-printing in browsers that block popups).

Add a @media print rule so the buttons remain visible on screen but
disappear from the printed receipt.

Test plan:
1. Disable browser popups (Chrome: "Don't allow sites to send pop-ups
   or use redirects").
2. Enable FinePaymentAutoPopup.
3. Complete a POS sale.
4. On the receipt page, choose Print to PDF (or trigger auto-print).
5. Verify the printed/PDF output contains only the receipt body — no
   Print receipt or Close buttons.
6. Verify the buttons remain visible on screen.

Signed-off-by: Andrew Fuerste Henry <andrew@bywatersolutions.com>
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>

koha-tmpl/intranet-tmpl/prog/css/printreceiptinvoice.css

@@ -341,3 +341,9 @@ fieldset {
 #cataloguing_additem_itemlist {
 	overflow : visible !important;
 }
+
+@media print {
+    .no-print {
+        display: none;
+    }
+}