Array parser fails on just spreading `none`

[CMDJojo]

#let x=(..none) doesn't parse as intended: it should parse as spreading none into an array but it parses as spreading it into a dict. Since the array parser has priority over the dictionary parser, the error is in the array parser. This issue leads to the test spread-09 not being truthful; before #46 it simply failed to parse but now it fails to run due to this parser bug.