Upgrade to stylelint 15 (#22944)

- Upgrade stylelint and plugin
- Change ruleset to a explicit one, with all deprecated rules removed
- Fix new issues detected by value validation

For `overflow: overlay` see
https://github.com/stylelint/stylelint/issues/6667

web_src/less/_base.less

@@ -226,7 +226,7 @@ body {
 
 @supports (overflow: overlay) {
   body {
-    overflow: overlay;
+    overflow: overlay; // stylelint-disable-line
     scrollbar-gutter: stable;
   }
 }