Resolve #3394413 "Basic pipeline"

Closes #3394413

The goal here is to add a basic pipeline that doesn't run any tests, but builds successfully. The goal is to have a core clone with the Automatic Updates and Package Manager modules converted to core modules.

scripts/src/ConverterCommand.php

@@ -61,7 +61,7 @@ class ConverterCommand extends Command {
    * {@inheritdoc}
    */
   protected function execute(InputInterface $input, OutputInterface $output) {
-    $this->core_dir = $input->getArgument('core_dir');
+    $this->core_dir = realpath($input->getArgument('core_dir'));
     $this->core_branch = $input->getArgument('core_branch');
     $this->contrib_branch = $input->getArgument('contrib_branch');
     $this->package_manager_only = $input->getOption('package_manager_only');
@@ -112,7 +112,6 @@ class ConverterCommand extends Command {
 
     // Switch to the core directory and require all of the packages there are in
     // this module's composer.json require section.
-    chdir('core');
     $require_section = $this->getContribModuleComposerJsonSection('require');
     // Hardcode symfony version to 6.4 for core.
     $core_symfony_version_update = function ($package_name, $version): string {
@@ -123,10 +122,8 @@ class ConverterCommand extends Command {
     };
     foreach ($require_section as $package_name => $version) {
       $version = $core_symfony_version_update($package_name, $version);
-      static::executeCommand("composer require $package_name:$version --no-update");
+      static::executeCommand("composer require $package_name:$version --no-update --working-dir={$this->core_dir}/core");
     }
-    // Switch back to the parent directory.
-    chdir('..');
     // Run composer update for just this packages.
     static::executeCommand("composer update  " . implode(' ', array_keys($require_section)));