I've taken this list and filtered out words that have other parts-of-speech according to wordpos. It went from 28,479 lines down to 23,799 lines. wordpos
definitely isn't perfect, so it's likely that there are many words still in this list that have other part-of-speech values. Here's the code I used:
const fetch = require('node-fetch');
const WordPOS = require('wordpos');
const wordpos = new WordPOS();
(async function() {
let text = await fetch("https://raw.githubusercontent.com/taikuukaits/SimpleWordlists/master/Wordlist-Adjectives-All.txt").then(r => r.text());
let adjectives = text.replace(/\r/g, "").split("\n");