perf: use woff2 format for the inter font

This massively decreases the size of the font file (~ 800kb -> 20kb) and therefore its loading time. The old `.ttf` format is still being kept as a fallback, though all modern browsers support the `woff2` format.

services/idp/src/app.css

@@ -1,7 +1,7 @@
 /* additional css on top of kpop */
 @font-face {
   font-family: Inter;
-  src: url(./fonts/inter.ttf) format('truetype');
+  src: url(./fonts/inter.woff2) format('woff2'), url(./fonts/inter.ttf) format('truetype');
   font-weight: 100 900;
   font-style: oblique 0deg 12deg;
 }