refactor: stylelint optimization

Author: mfranzke

source/css/db-ui-base.scss

@@ -7,7 +7,7 @@
 // stylelint-disable-next-line import-notation, @stylistic/string-quotes
 @import "../../build/scss/variables";
 // stylelint-disable-next-line @stylistic/string-quotes
-@import url("variables.css");
+@import "variables.css";
 
 /* body {
 	font-family: var(--asset-font-db-screensans-regular-name);