The Inter typeface is very versatile and has many different options and variants, including more distinguishable uppercase i and lowercase L. The article just installed the base version as an example. https://rsms.me/inter/
Fair, they're pretty common but most fonts support OpenType variations which let you change parts of the fonts to other variants. Having a variant with distinct l's and I's is pretty common and Inter supports this.
Like most modern fonts, it supports a lot of OpenType features, so this can be changed dynamically. Changing some settings by default has already been mentioned in the discussion around the change.
IIRC this issue is mentioned in the gitlab discussions (from months ago ... not sure how this became news suddenly); they're looking to patch Inter if they decide to use it as the UI font.