Offset alignment isn't checked in list addition

[nameexhaustion]

Checks

• I have checked that this issue has not already been reported.
• I have confirmed this bug exists on the latest version of Polars.

Reproducible example

import polars as pl

a = pl.Series("a", [[1, 1], [1, 1, 1]])
b = pl.Series("b", [[1, 1, 1], [1, 1]])

print(a + b)
# shape: (2,)
# Series: 'a' [list[i64]]
# [
# 	[2, 2]
# 	[2, 2, 2]
# ]

Log output

No response

Issue description

Alignment of list offsets isn't checked

Expected behavior

Should raise

Installed versions

main