Remove dev.semgrep.dev from update-registry job

[mschwager]

It looks like this job started failing within the past 3 months: https://github.com/trailofbits/semgrep-rules/actions/workflows/update-semgrep-registry.yml.

I'm seeing the same behavior locally:

$ curl --fail -X POST -L https://dev.semgrep.dev/api/admin/update-registry
curl: (22) The requested URL returned error: 404
$ curl --fail -X POST -L https://staging.semgrep.dev/api/admin/update-registry
{"status":"Started processing"}
$ curl --fail -X POST -L https://semgrep.dev/api/admin/update-registry
{"status":"Started processing"}

cc @LewisArdern does this look correct to you?

[GrosQuildu]

Asked the r2c team for details, let's wait for response.