EntryIndex.$newEntryBtn doesn't update sources on selectSite

[Anubarak]

Description

The Craft.EntryIndex class doesn't properly update the available publishableSections in the $newEntryBtnGroup. Currently this code is executed to display all available Sections inside the New entry button, thus users can select all of their sections when they want to create a new entry - no matter if the section is even available in the current site or not. Here is the code

for (i = 0; i < this.publishableSections.length; i++) {
    var section = this.publishableSections[i];

    if (this.settings.context === 'index' || section !== selectedSection) {
        href = this._getSectionTriggerHref(section);
        label = (this.settings.context === 'index' ? section.name : Craft.t('app', 'New {section} entry', {section: section.name}));
        menuHtml += '<li><a ' + href + '">' + Craft.escapeHtml(label) + '</a></li>';
    }
}

publishableSections contains all sections, so it doesn't care if they are enabled or not

publishableSections: [
    {% if isInstalled and currentUser is defined and currentUser %}
        {% for section in craft.app.sections.getEditableSections() %}
            {% if section.type != 'single' and currentUser.can('createEntries:'~section.id) %}
                {
                    id: {{ section.id }},
                    name: "{{ section.name|t('site')|e('js') }}",
                    handle: "{{ section.handle|e('js') }}",
                    type: "{{ section.type }}",
                    entryTypes: [
                        {% for entryType in section.getEntryTypes() %}
                            {
                                id: {{ entryType.id }},
                                name: "{{ entryType.name|t('site')|e('js') }}",
                                handle: "{{ entryType.handle|e('js') }}"
                            }{% if not loop.last %},{% endif %}
                        {% endfor %}
                    ]
                }{% if not loop.last %},{% endif %}
            {% endif %}
        {% endfor %}
    {% endif %}
],

It just checks if the user can edit the section or not.

Steps to reproduce

1. Create multiple sites and multiple different sections
2. Disable some of those sections for certain sites
3. Click on the "New Entry" button and see all those sections as available sources no matter if they are enabled for the current selected site or not

Steps to fix this

1. include the ids of all available sites in the publishableSections object
2. include an additional condition if (this.settings.context === 'index' || section !== selectedSection) { if the current selected siteId this.siteId is in the array of site ids.

if ((this.settings.context === 'index' || section !== selectedSection) && section.availableSites.includes(this.siteId) {

and

availableSites: {{ section.getSiteIds|json_encode|raw }},