groups: rename account used from wg-k8s-infra-api to sig-k8s-infra-groups-api

[spiffxp]

Related:

• Followup to: https://github.com/kubernetes/community/issues/6036
• Related to: https://github.com/kubernetes/steering/issues/213

We should rename this account to match the fact that it belongs to a SIG and not a WG.

While we're here... I think, but am not entirely sure, that we cannot have multiple service accounts linked to a single google workspace account for delegated domain wide authority. If this is in fact the case, we should rename the account to be more specific to its purpose.

[spiffxp]

/kind cleanup /sig k8s-infra /area groups /area access /priority backlog /milestone v1.23

[spiffxp]

/assign

[ameukam]

/milestone v1.24

[ameukam]

/milestone clear /lifecycle frozen