Remove unused warning during bulk delete

[Arnei]

This patch removes a warning in the bulk delete modal that claims the user is not authorized.
Removing this for two reasons:

1. The warning claims to have done an authorization check. That check is never performed, but the warning is always displayed nonetheless.
2. Users currently cannot select events if they don't have write access on them anyway (they don't show up in the events table in the first place), so there is no need to perform such an authorization check in the first place.

How to test this

Can be tested as usual.

[github-actions]

Use docker or podman to test this pull request locally.

Run test server using develop.opencast.org as backend:

podman run --rm -it -p 127.0.0.1:3000:3000 ghcr.io/opencast/opencast-admin-interface:pr-1049

Specify a different backend like stable.opencast.org:

podman run --rm -it -p 127.0.0.1:3000:3000 -e PROXY_TARGET=https://stable.opencast.org ghcr.io/opencast/opencast-admin-interface:pr-1049

It may take a few seconds for the interface to spin up.
It will then be available at http://127.0.0.1:3000.
For more options you can pass on to the proxy, take a look at the README.md.

[github-actions]

This pull request is deployed at test.admin-interface.opencast.org/1049/2025-01-09_11-51-49/ .
It might take a few minutes for it to become available.