perf(autoloading): Add authoritative autoloader for files_external

[ChristophWurst]

• Resolves: #

Summary

Extracted from #36112 for green CI.

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[skjnldsv]

Should we also have a dedicated workflow to check for outdated autoloaders here too?

[ChristophWurst]

Should we also have a dedicated workflow to check for outdated autoloaders here too?

#36112 f4ff908 addresses that.

[ChristophWurst]

Should we also have a dedicated workflow to check for outdated autoloaders here too?

We have a workflow to check for outdated workflows. The issue here is that they were missing. And the update script skips apps without an autoloader.

[ChristophWurst]

**Samba Kerberos SSO / kerberos (pull_request) ** Failing after 1m

It wasn't me: https://github.com/nextcloud/server/actions/workflows/smb-kerberos.yml

[ChristophWurst]

Shall we do this?

[icewind1991]

/rebase

[ChristophWurst]

Failed to connect to localhost port 9000 after 0 ms: Connection refused