fix(framework): Fix openui5 css varaibles detection (#1933)

Change the regex to detect the openui5 CSS variables properly as from 1.79 the CSS Variables filename has changed to css_variables.css (previously css-varaibles.css with dash).
But, the script will match the old name with "-" dash as well, if we need to support it, otherwise we can leave "_" only to support the latest name.

FIXES: #1932

Author: ilhan007

packages/base/src/features/OpenUI5Support.js

@@ -75,7 +75,7 @@ const cssVariablesLoaded = () => {
 		return;
 	}
 
-	return !!link.href.match(/\/css-variables\.css/);
+	return !!link.href.match(/\/css(-|_)variables\.css/);
 };
 
 const OpenUI5Support = {