fix: lint errors

Author: TomPridham

sources/accessible-name-and-description.ts

@@ -362,8 +362,9 @@ export function computeTextAlternative(
 		if (pseudoElement !== undefined) {
 			return _getComputedStyle(el, pseudoElement);
 		}
-		if (computedStyles.has(el)) {
-			return computedStyles.get(el)!;
+		const cachedStyles = computedStyles.get(el);
+		if (cachedStyles) {
+			return cachedStyles;
 		}
 		const style = _getComputedStyle(el, pseudoElement);
 		computedStyles.set(el, style);

sources/polyfills/MapLike.ts

@@ -5,7 +5,7 @@ declare global {
 		delete(key: K): boolean;
 		forEach(
 			callbackfn: (value: V, key: K, map: Map<K, V>) => void,
-			thisArg?: any,
+			thisArg?: this,
 		): void;
 		get(key: K): V | undefined;
 		has(key: K): boolean;
@@ -56,8 +56,8 @@ class MapLike<K, V> {
 		return this;
 	}
 	forEach(
-		callbackfn: (value: V, key: K, map: MapLike<K, V>) => void,
-		thisArg?: any,
+		_callbackfn: (value: V, key: K, map: MapLike<K, V>) => void,
+		_thisArg?: this,
 	): void {}
 }