Parse error when annotation and a `const` variable are on the same line

Input:

```gdscript
func test_warnings():
@warning_ignore("unused_local_constant") const unused_local_constant = 1
```

Error: `the input GDScript code contains parse errors`

This code is fine:

```gdscript
func test_warnings():
@warning_ignore("unused_local_constant") var unused_local_constant = 1
```

This is also fine (but it gets formatted into the input code and you get the same error when formatting again):

```gdscript
func test_warnings():
@warning_ignore("unused_local_constant")
const unused_local_constant = 1
```

Reproduce the reported annotation-plus-const input and compare it with the working var and multiline const cases. Trace the formatter/parser entry point that handles annotations and local declarations; done means the one-line const form parses successfully and repeated formatting does not reintroduce the error.

Scritto dal modello di indicizzazione a partire dal testo della issue.