ci: add filetype.rs autolabel

Signed-off-by: Christina Sørensen <christina@cafkafk.com>

.github/labeler.yml

@@ -1,5 +1,8 @@
 "features › icon":
   - src/output/icons.rs 
 
+"features › ui":
+  - src/info/filetype.rs 
+
 "packaging › snap":
   - snap/**/*