`---@cast` annotation doesn't respect scope rules

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### How are you using the lua-language-server?

Visual Studio Code Extension (sumneko.lua)

### Which OS are you using?

Windows

### What is the issue affecting?

Type Checking

### Expected Behaviour

The `---@cast` annotation should respect Lua scoping rules.

### Actual Behaviour

Let's consider:
```lua
--- @class foo
--- @field a number

--- @class bar
--- @field b string

--- @type { [integer]: foo|bar }
local array = {}

for i, instance in ipairs(array) do
if instance.a then
-- First if block
--- @cast instance foo
end

if instance.b then
-- Second if block
end
end
```
In the first if block, we cast the `instance` to the `foo` type. When hovering over the `instance` variable in the second if block we can see its type is `foo`. It would be expected for its type to be `bar` since the `---@cast` happened in different scope.

### Reproduction steps

1. Copy-paste the given example code into your text editor.
2. Hover over the `instance` variable in the second if block.
3. See the error in the popup.

### Additional Notes

_No response_

### Log File

_No response_

Start by reproducing the issue with the supplied Lua example in the Visual Studio Code extension and inspect how type checking handles the two if-block scopes. Done means the cast to foo applies only within the first block, while the instance in the second block retains the appropriate inferred type instead of foo.

Written by the indexing model from the issue text.