Remove Int64 from encode_signed_varint! signature

[arhik]

• Int64 causes InexactError when passed because of call to UInt64(value) in the body of function.
• Zigzag-encoded values and float bits are always unsigned integers but might be reachable from a variant of same function in basic.jl.
• Fixes potential runtime error in bytecode encoding

cuTile.jl/src/bytecode/writer.jl

Lines 299 to 302 in e5e1fa5

	function encode_signed_varint!(buf::Vector{UInt8}, value::Union{UInt16, UInt32, UInt64})
	# For float bits, encode as unsigned varint
	encode_varint!(buf, UInt64(value))
	end

Fixes #41