ci(release): build and release a nightly twice a day

- Remove other/nightly, the nightly channel uses the production files, so there are no longer two copies to keep in sync
- sync-cdn.sh --nightly syncs the files of the commit the nightly is built from to /coolify/nightly on the CDN, with the nightly version in its versions.json and in /coolify/release.json, and pushes them straight to main of coollabs-cdn
- version.sh picks the branch the nightly comes from, the release branch of the next version after the newest stable one or next, and names the version <preview>.<YYYYMMDD>.<N>
- The image is labeled with its version and commit, the nightly workflow reads both from the image nightly points at to count up N and to skip a run without a new commit

tests/Unit/InstallScriptRootUserEnvTest.php

@@ -41,7 +41,7 @@ function writeRootUserCredentialsWithInstallScript(string $scriptPath, array $cr
     return Dotenv::parse($contents);
 }
 
-$installScripts = ['stable install' => 'scripts/install.sh', 'nightly install' => 'other/nightly/install.sh'];
+$installScripts = ['stable install' => 'scripts/install.sh'];
 
 $credentials = [
     'username with a space' => ['ROOT_USERNAME', 'Coolify Lab'],