Fix: 修复Python Online板卡下对本地目录操作对象的缓存没有在退出后清除

boards/default_src/python_pyodide/others/filesystem-fs.js

@@ -33,13 +33,13 @@ export default class FileSystemFS extends FS {
         if (permissionStatus !== 'granted') {
             throw new Error('readwrite access to directory not granted');
         }
-        await set('mixly-pyodide-fs', directoryHandle);
+        await this.setFSCache(directoryHandle);
         this.#fs_ = new WebAccessFSExt(directoryHandle);
         return directoryHandle;
     }
 
     async loadFS() {
-        let directoryHandle = await get('mixly-pyodide-fs');
+        let directoryHandle = await this.getFSCache();
         if (!directoryHandle) {
             return null;
         }
@@ -51,6 +51,14 @@ export default class FileSystemFS extends FS {
         return directoryHandle;
     }
 
+    async getFSCache() {
+        return get('mixly-pyodide-fs');
+    }
+
+    async setFSCache(data) {
+        await set('mixly-pyodide-fs', data);
+    }
+
     async createFile(filePath) {
         return this.#fs_.createFile(filePath, '');
     }