Bug 34973: (follow-up) Use lib/fontawesome for font location

It makes more sense to use lib/fontawesome/webfonts as the source
directory for Font Awesome font files rather than bootstrap/css/fonts.

Signed-off-by: Pedro Amorim <pedro.amorim@openfifth.co.uk>

koha-tmpl/opac-tmpl/bootstrap/css/src/_common.scss

@@ -1,6 +1,6 @@
 @use "~@fortawesome/fontawesome-free/scss/variables" with (
-    // customizing $font-path
-    $font-path: "./fonts"
+    // koha-tmpl/opac-tmpl/lib/fontawesome/webfonts
+    $font-path: "../../lib/fontawesome/webfonts"
 );
 @use "~@fortawesome/fontawesome-free/scss/fontawesome";
 @use "~@fortawesome/fontawesome-free/scss/fa" as fa;