Describe the bug

Parsing repeated open parens causes nu to consume many GBs of memory and crashing.

Found while trying to fuzz nu-parser's parse_with_keywords target.

This behavior sounds similar to #15241 in conceptual terms (i.e. many unclosed nested AST structures) but is different in manifestation that it does not fail with a stack overflow but a general memory leak.

More closely related in behavior to #13944

How to reproduce

use ulimit -m before launching the nu under test, to limit the consumed memory.
Type ((((((((((((((((((( into the repl (or a few more or less ( depending on the available memory)
Syntax highlighting stalls and the process gets killed.

Saving the same sequence to a script test.nu and running nu test.nu does not trigger for the same number of open ( and instead reports back with the error:

Error: nu::parser::unexpected_eof

  × Unexpected end of code.
   ╭─[/home/stefan/nushell/crates/nu-parser/fuzz/testrepr.nu:1:20]
 1 │ (((((((((((((((((((
   ·                    ┬
   ·                    ╰── expected closing )
   ╰────

Expected behavior

No memory leak, no stack overflow, just appropriate parse errors

Configuration