fix(website): skip runtime archive for websites on a local PHP runtime - #14409

What this PR does / why we need it?

Fixes #13900.

Backing up a website that runs on a PHP runtime whose source is "local" always fails, both from the backup page and from a scheduled backup:

备份 [www.xxx.com] 失败: stderr: tar: php81l: Cannot stat: No such file or directory

A local runtime is only a database record. RuntimeService.Create returns before anything is written to disk, so /opt/1panel/runtime/php/<name> never exists. doWebsiteBackup still calls handleRuntimeBackup for every runtime website, and that tars the missing directory.

Restoring such a website has the same problem: recover first takes a rollback backup (which fails the same way), and then expects a <alias>.runtime.tar.gz inside the archive.

Summary of your change

• doWebsiteBackup: skip the runtime archive when the runtime's resource is local. The site files, nginx config and database are still backed up.
• handleWebsiteRecover: skip the runtime restore for these websites, since their backups never contain a runtime archive.
• Add TestWebsiteBackupWithLocalPHPRuntime, which backs up a website on a local PHP runtime. It fails without the change with the tar ... Cannot stat error and passes with it (run on ubuntu-latest; the repo has no Go test CI). In that run TestAppStoreIndexUsesCacheUntilRevisionChanges fails both with and without this change, on a TLS error from the test's fake server.

Please indicate you've done the following:

• Made sure tests are passing and test coverage is added if needed.
• Made sure commit message follow the rule of Conventional Commits specification.
• Considered the docs impact and opened a new docs issue or PR with docs changes if needed.