et-al-subsequent-min / et-al-subsequent-use-first
If used, the values of these attributes replace those of respectively
et-al-min and et-al-use-first for subsequent cites
(cites referencing earlier cited items).
Therefore we need to fallback if et_al_subsequent are None
Fixes #10
Also fixes typst/hayagriva#141, and fixes typst/typst#3699
From the CSL Spec it is suggested that
Therefore we need to fallback if
et_al_subsequent
areNone
Fixes #10 Also fixes typst/hayagriva#141, and fixes typst/typst#3699