Casting an otherwise unused variable in a block preserves the cast outside of block

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

Any casts inside a block should not be maintained once leaving that block.

Actual Behaviour

Type cast is maintained even after the block in which the variable was cast if and only if the variable was not used in that block.

Reproduction steps

This is incorrect:

---@type number|string
local i
if true then --can be `false` or any other logical
  ---@cast i number
  local _ = 0 --not referencing variable `i` that was cast above
end
local j = i --type of j is `number`, should be `number|string`

This is correct:

---@type number|string
local i
if true then --can be `false` or any other logical
  ---@cast i number
  local _ = i -- referencing variable `i` that was cast above
end
local j = i --type of j is `number|string`

Additional Notes

No response

Log File

No response

Reproduce both Lua snippets through the Visual Studio Code extension and compare the inferred type of j after the block. Trace the type-checking path for @cast handling when the cast variable is unused, then verify that the cast does not survive the block while the in-block reference case remains correct.