In SymbolKindAbstract value_set should be a list type based on the spec.

[karthiknadig]

pygls/pygls/types.py

Lines 1119 to 1121 in 144bbc0

	class SymbolKindAbstract:
	def __init__(self, value_set: SymbolKind):
	self.valueSet = value_set

This should probably be:

def __init__(self, value_set: List[SymbolKind]):

https://microsoft.github.io/language-server-protocol/specifications/specification-current/#workspace_symbol