the specification is "queer relationships between women" this is a game jam built around the lesbian identity and women loving women, to tell stories about romantic and sexual interaction between them. as to make it more inclusive it has been broadened to include other variations that arent strictly lesbian in the standard sense; which is apparent in the further clarification "This includes: lesbian, bi, trans, non-binary, aro, ace, pan, any female-identified LGBTQIA characters. Trans masc and non-binary lesbians are also allowed to be the focus of any projects."
if you are only making a story that revolves around deep friendship it doesnt count as itself, but for example can count if it still describes the "queer female experience." ie someone in the story is gay and the romance aspect just isnt the main focus.
ultimately, the jam has been created to motivate people to make games regarding these minorities to create representation because there are not enough of these stories in the world. does your game contribute to that?
in the end, question why you want to include your game in the jam but if you think your game is yuri in the spirit enough that you would put for example the itch.io tags of lgbt and/or yuri on it then go for it and submit