Improve usage of css-functions-list in function-no-unknown (#5916)

This change bumps `css-functions-list` from 3.0.0 to 3.0.1.
See https://github.com/niksy/css-functions-list/releases/tag/v3.0.1

```shell
npm i css-functions-list
```

lib/rules/function-no-unknown/index.js

@@ -1,7 +1,6 @@
 'use strict';
 
 const fs = require('fs');
-const { URL } = require('url');
 const valueParser = require('postcss-value-parser');
 const functionsListPath = require('css-functions-list');
 
@@ -44,8 +43,7 @@ const rule = (primary, secondaryOptions) => {
 			return;
 		}
 
-		const path = new URL(functionsListPath.toString(), 'file://');
-		const functionsList = JSON.parse(fs.readFileSync(path, 'utf8'));
+		const functionsList = JSON.parse(fs.readFileSync(functionsListPath.toString(), 'utf8'));
 
 		root.walkDecls((decl) => {
 			const { value } = decl;

package.json

@@ -111,7 +111,7 @@
     "balanced-match": "^2.0.0",
     "colord": "^2.9.2",
     "cosmiconfig": "^7.0.1",
-    "css-functions-list": "^3.0.0",
+    "css-functions-list": "^3.0.1",
     "debug": "^4.3.3",
     "execall": "^2.0.0",
     "fast-glob": "^3.2.11",