fix(themes): drop topline_website value from <li> class to avoid filter collision (#8800)

When topline_website is "icon", the <li> renders class="item website
icon". Bare .icon rules in Nord and Dark apply a filter that cascades
onto the favicon <img> inside, so article-list favicons render tinted
in icon-only mode. No theme CSS targets the unprefixed value; layout
modes are driven from the parent <ul> (.websiteicon, .websitename).

Co-authored-by: Bjørn A. Andersen <polybjorn@users.noreply.github.com>

app/views/helpers/index/normal/entry_header.phtml

@@ -47,7 +47,7 @@
 	}
 
 	if ($topline_website !== 'none'):
-	?><li class="item website <?= $topline_website ?>">
+	?><li class="item website">
 		<a href="<?= _url('index', 'index', 'get', 'f_' . $this->feed->id()) ?>" class="item-element" title="<?= _t('gen.action.filter') ?>: <?= $this->feed->name() ?>">
 			<?php if (FreshRSS_Context::userConf()->show_favicons && 'name' !== $topline_website): ?><img class="favicon" src="<?= $this->feed->favicon() ?>" alt="✇" loading="lazy" /><?php endif; ?><?php if ('icon' !== $topline_website): ?><span class="websiteName"><?= $this->feed->name() ?></span><?php endif; ?>
 		</a>