使用注解遇到的问题.

| 名称 | 版本 |
| :-: | :-: |
| visual studio code | v1.52.1 |
| lua-language-server | v1.7.4 |

## 遇到的问题

使用注解`@language`的语法高亮不生效.

## 测试方式

### 1. 源码文件是这样的:

```lua
local str = [[{
"code": 200
}]]

---@language JSON
local js1 = [[{
"code": 200
}]]

---@language Json
local js2 = [[{
"code": 200
}]]

---@language json
local js3 = [[{
"code": 200
}]]

print(str, js1, js2, js3)
```

### 2. 实际的显示效果:

### 3. 可以确定和主题无关, 即使禁用与卸载主题依然如此.

Reproduce the report in Visual Studio Code v1.52.1 with lua-language-server v1.7.4 using the Lua sample containing the @language JSON, Json, and json annotations. Compare the rendered highlighting with and without the annotations; done means the reported annotation behavior is understood and the expected highlighting outcome is confirmed. No source files or tests are named in the issue.

Written by the indexing model from the issue text.