Bug: Invalid indentation allowed after `do`

Bug report (minor)

### Input Code
```coffee
foo = do
bar = getBar()
indented
indented
notIndented
notIndented
```

### Expected Behavior
Compilation error: unexpected indentation of `indented` on line 3

### Current Behavior
```js
var bar, foo;

foo = (bar = getBar())();

indented;

indented;

notIndented;

notIndented;
```

### Analysis
The token stream incorrectly has no `DEDENT` token:

`[IDENTIFIER foo] [= =] [DO do] [IDENTIFIER bar] [= =] [IDENTIFIER getBar] [CALL_START (] [CALL_END )] [TERMINATOR \n] [IDENTIFIER indented] [TERMINATOR \n] [IDENTIFIER notIndented] [TERMINATOR \n]`

Hopefully not too hard a fix...

### Context
The current behavior (pointed out by a user) could lead users to write buggy code, because it seems like the indented code is executed "within" the `do`, but it isn't. (Unlike e.g. if the `do` was followed by `->` as is usual.)

### Environment

* CoffeeScript version: 2.7.0
* Node.js version: 19.9.0

Start by reproducing the CoffeeScript 2.7.0 example and inspecting the token stream around `do`, indentation, and `DEDENT`. The fix is complete when the shown input produces a compilation error for the unexpected indentation instead of compiling the indented statements, with regression coverage for this case.

Written by the indexing model from the issue text.