content: remove hoisting exercise pilot

The quiz exercise was only an early cross-format pilot and no longer follows the finalized JavaScript manifest workflow. Remove its markers, definitions, and obsolete aggregate translation source before the JavaScript rollout begins.

Author: yangshun

langnostic.config.ts

@@ -17,10 +17,6 @@ export default {
           source: './questions/*/en-US.mdx',
           target: './questions/*/{locale}.mdx',
         },
-        {
-          source: './questions/*/exercises/en-US.mdx',
-          target: './questions/*/exercises/{locale}.mdx',
-        },
       ],
     },
   ],

questions/explain-hoisting/en-US.mdx

@@ -171,8 +171,6 @@ var expressed = function () {
 };
 ```
 
-<Exercise id="function-declaration-vs-expression" />
-
 - `declared()` returns `'function declaration'`. Function declarations are fully hoisted — both the identifier binding and the function body are available from the top of the scope.
 - `expressed()` throws `TypeError: expressed is not a function`. The `var expressed` binding is hoisted and initialized to `undefined`, but the assignment of the function expression happens at its source location. Calling `undefined()` produces the `TypeError`.
 

questions/explain-hoisting/exercises/en-US.langnostic.json

@@ -32,8 +32,6 @@ var bar = function () {
 console.log(bar); // [Function: bar]
 ```
 
-<Exercise id="function-declaration-vs-expression" />
-
 Variáveis declaradas via `let` e `const` também sofrem o hoisted. No entanto, ao contrário de `var` e `function`, eles não são inicializados e acessá-los antes que a declaração resulte em uma exceção `ReferenceError`. A variável está em uma "zona temporária morta" desde o início do bloco até que a declaração seja processada.
 
 ```js

questions/explain-hoisting/exercises/en-US.mdx

@@ -104,8 +104,6 @@ function foo() {
 }
 ```
 
-<Exercise id="function-declaration-vs-expression" />
-
 这同样适用于生成器 (`function*`)、异步函数 (`async function`) 和异步函数生成器 (`async function*`)。
 
 ### `import` 语句的提升