Redirect from `{repo}/issues/new` to `{repo}/issues/new/choose` when blank issues are disabled (#26813) (#26847)
Backport #26813 by @JakobDev
You can currently visit `{repo}/issues/new` and create a blank issue,
even if it's disabled. This PR fixes this,
Fixes https://codeberg.org/forgejo/forgejo/issues/1356
Co-authored-by: JakobDev <jakobdev@gmx.de>