(🐞) Note reported on wrong line

c: str
a: range | object
a + (
    "".join(
        "" + 1
    )
)

test.py:3:1: error: Unsupported left operand type for + ("range")  [operator]
    a + (
    ^
test.py:3:1: error: Unsupported left operand type for + ("object")  [operator]
    a + (
    ^
test.py:5:14: error: Unsupported operand types for + ("str" and "int")  [operator]
            "" + 1
                 ^
test.py:5:14: note: Left operand is of type "range | object"

In this instance, this note is completely irrelevant and very confusing.
Left operand is of type "range | object"?

This is coming from checkexpr.check_op/MessageBuilder.warn_operand_was_from_union

Reproduce the diagnostic with the Python snippet in the issue, then inspect checkexpr.check_op and MessageBuilder.warn_operand_was_from_union to trace why the union note is attached to the inner expression. Done means the reported note is no longer irrelevant or is associated with the correct operand; add or update a regression test covering this example.