Garbage colleciton fix

src/reader.js

@@ -294,8 +294,14 @@ export class ZimReader {
 	/** Opens the archive and parses its header + mimetype list. */
 	async open() {
 		this.#fd = await fs.promises.open(this.path, 'r');
-		await this.#readHeader();
-		await this.#readMimeTypes();
+		try {
+			await this.#readHeader();
+			await this.#readMimeTypes();
+		} catch (e) {
+			await this.#fd.close();
+			this.#fd = null;
+			throw e;
+		}
 		return this;
 	}