meson format crashes in add_nl_after

[blue42u]

Describe the bug
meson format crashes when attempting to format one of our meson.build files.

To Reproduce

# Minimized meson.build
test(
  args: [
    shared_library(
      f'tstlib-@name@',
      build_by_default: false,
      override_options: opt,
    ),
  ],
)

test(
  should_fail: (
    settings.get('x', false) and not settings['y']
    and dep.version().version_compare('>=1.2.3')
  ),
)

$ meson format meson.build
Traceback (most recent call last):
  File ".../meson/mesonbuild/mesonmain.py", line 188, in run
    return options.run_func(options)
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../meson/mesonbuild/mformat.py", line 937, in run
    formatted = formatter.format(code, src_file)
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File ".../meson/mesonbuild/mformat.py", line 861, in format
    ast.accept(ArgumentFormatter(self.current_config))
  File ".../meson/mesonbuild/mparser.py", line 251, in accept
    func(self)
  File ".../meson/mesonbuild/ast/visitor.py", line 216, in visit_CodeBlockNode
    i.accept(self)
  File ".../meson/mesonbuild/mparser.py", line 251, in accept
    func(self)
  File ".../meson/mesonbuild/mformat.py", line 591, in visit_FunctionNode
    node.args.accept(self)
  File ".../meson/mesonbuild/mparser.py", line 251, in accept
    func(self)
  File ".../meson/mesonbuild/mformat.py", line 610, in visit_ArgumentNode
    super().visit_ArgumentNode(node)
  File ".../meson/mesonbuild/ast/visitor.py", line 317, in visit_ArgumentNode
    val.accept(self)
  File ".../meson/mesonbuild/mparser.py", line 251, in accept
    func(self)
  File ".../meson/mesonbuild/mformat.py", line 668, in visit_ParenthesizedNode
    node.inner.accept(self)
  File ".../meson/mesonbuild/mparser.py", line 251, in accept
    func(self)
  File ".../meson/mesonbuild/ast/visitor.py", line 200, in visit_AndNode
    self.visit_BinaryOperatorNode(node)
  File ".../meson/mesonbuild/ast/visitor.py", line 179, in visit_BinaryOperatorNode
    node.right.accept(self)
  File ".../meson/mesonbuild/mparser.py", line 251, in accept
    func(self)
  File ".../meson/mesonbuild/mformat.py", line 575, in visit_MethodNode
    node.source_object.accept(self)
  File ".../meson/mesonbuild/mparser.py", line 251, in accept
    func(self)
  File ".../meson/mesonbuild/mformat.py", line 580, in visit_MethodNode
    node.args.accept(self)
  File ".../meson/mesonbuild/mparser.py", line 251, in accept
    func(self)
  File ".../meson/mesonbuild/mformat.py", line 649, in visit_ArgumentNode
    self.add_nl_after(comma, self.level)
  File ".../meson/mesonbuild/mformat.py", line 545, in add_nl_after
    if not node.whitespaces.value or node.whitespaces.value == ' ':
           ^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'value'

ERROR: Unhandled python exception

    This is a Meson bug and should be reported!

Expected behavior
meson format should format the code without raising an unhandled exception.

system parameters

• Not a build
• Ubuntu 24.04
• Python 3.12.3
• Meson 1.4.99 (aa9b7b9)

[eli-schwartz]

/cc @bruchar1