Allowed installation of SimpleSAMLphp modules.

[barbun]

Issue

• The current composer.json sets:

  "simplesamlphp/composer-module-installer": false

  This disables SimpleSAMLphp’s Composer Module Installer — the plugin responsible for automatically installing and registering additional SimpleSAMLphp modules.

• As a result, modules such as simplesamlphp/simplesamlphp-assets-base are not automatically detected or enabled by SimpleSAMLphp.

• When using HTTP-POST bindings, SAML authentication data is transmitted via an intermediary form page. Without the simplesamlphp-assets-base module, this form lacks the auto-submit functionality, causing users to get stuck on that intermediary page until they manually submit it.

• Keeping "simplesamlphp/composer-module-installer": true is the recommended approach, ensuring that all SimpleSAMLphp modules (e.g. assets, themes, or authentication handlers) are automatically registered during installation.

Proposed Solution

• Update composer.json to:

  "simplesamlphp/composer-module-installer": true

• This change restores automatic module installation and registration, allowing modules like simplesamlphp/simplesamlphp-assets-base to function as intended.
• It resolves the HTTP-POST binding issue and improves maintainability by ensuring all required modules are consistently managed by Composer.

[mingsong-hu]

@barbun As discussed, I created another PR (govCMS/lagoon#532) for Lagoon to achieve the goal via a different approach.