REL: prepare v0.15.0 release

[lucascolley]

No description provided.

[ev-br]

LGTM.
Agreed that cutting a release makes sense.
Want to do the honours Lucas?

[lucascolley]

@ev-br how does one trigger the release again? I pushed https://github.com/data-apis/array-api-compat/releases/tag/1.15 but that doesn't seem to have triggered the workflow

[ev-br]

https://data-apis.org/array-api-compat/dev/releasing.html recommends to delete a tag and push it again.
If that doesn't work, I wonder if the build system update is breaking something (no idea what or how)

[lucascolley]

alright it worked now, maybe gh-433 made a difference, or maybe it was just a blip

[ev-br]

Brilliant, thanks Lucas.
While it's still fresh in memory: what did you do exactly that worked?

[lucascolley]

git tag -d 1.15
git push upstream --delete 1.15
git tag -a 1.15
git push upstream 1.15