Factor away HeadLink helper.

Author: demiankatz

module/VuFindTheme/Module.php

@@ -110,11 +110,10 @@ public function getViewHelperConfig()
                 View\Helper\AssetPipeline::class => View\Helper\AssetPipelineFactory::class,
                 View\Helper\FootScript::class => View\Helper\PipelineInjectorFactory::class,
                 View\Helper\ImageLink::class => View\Helper\ImageLinkFactory::class,
-                View\Helper\HeadLink::class => View\Helper\PipelineInjectorFactory::class,
                 View\Helper\HeadScript::class => View\Helper\PipelineInjectorFactory::class,
                 View\Helper\ParentTemplate::class => View\Helper\ParentTemplateFactory::class,
                 View\Helper\InlineScript::class => View\Helper\PipelineInjectorFactory::class,
-                View\Helper\Slot::class => View\Helper\PipelineInjectorFactory::class,
+                View\Helper\Slot::class => InvokableFactory::class,
                 View\Helper\TemplatePath::class => View\Helper\TemplatePathFactory::class,
                 View\Helper\SetupThemeResources::class => View\Helper\SetupThemeResourcesFactory::class,
             ],
@@ -124,7 +123,6 @@ public function getViewHelperConfig()
                 // Legacy alias for compatibility with pre-8.0 templates:
                 'headThemeResources' => View\Helper\SetupThemeResources::class,
                 'imageLink' => View\Helper\ImageLink::class,
-                \Laminas\View\Helper\HeadLink::class => View\Helper\HeadLink::class,
                 \Laminas\View\Helper\HeadScript::class => View\Helper\HeadScript::class,
                 \Laminas\View\Helper\InlineScript::class => View\Helper\InlineScript::class,
                 'parentTemplate' => View\Helper\ParentTemplate::class,