Remove sentry-kube repository conditional on PGBouncerSidecar macro

[mwarkentin]

us.gcr.io/sentryio (container registry) is deprecated / unused (https://github.com/getsentry/sentry-infra-tools/blob/main/sentry_kube/ext.py#L89C28-L89C45)

We don't need to handle url customization anymore: https://github.com/getsentry/sentry-infra-tools/blob/main/sentry_kube/ext.py#L136-L138

Fix / remove and create a new release of sentry-infra-tools.

Sidenote: Should macros be part of sentry-kube itself or can they be defined where they're used (eg. in ops repo)?