chore: Fix breaks caused by Array.isArray signature changes

I blame orta... microsoft/TypeScript#41984

Author: Gerrit0

src/lib/converter/converter.ts

@@ -145,7 +145,7 @@ export class Converter extends ChildableComponent<
         entryPoints: readonly string[],
         programs: ts.Program | readonly ts.Program[]
     ): ProjectReflection | undefined {
-        programs = Array.isArray(programs) ? programs : [programs];
+        programs = programs instanceof Array ? programs : [programs];
         this.externalPatternCache = void 0;
 
         const project = new ProjectReflection(this.name);

src/lib/utils/array.ts

@@ -148,7 +148,7 @@ export function flatMap<T, U>(
 
     for (const item of arr) {
         const newItem = fn(item);
-        if (Array.isArray(newItem)) {
+        if (newItem instanceof Array) {
             result.push(...newItem);
         } else {
             result.push(newItem);