[FIX] website_blog: fix latest blog tag color

Since commit [1], the color combination system has been introduced,
affecting the colors of elements in the snippets. For the "blog" page
cover, it wasn't adjusted to work with this color combination system.
This resulted in inconsistencies, like the "Latest blog" tag having
nearly the same background and text color. This is because some elements
are affected by the chosen color combinations, while others have a
hardcoded color in the XML template (for example, the "text-white" class
on the blog title link).

In this stable version, we address this by ensuring that the text color
of the "latest blog" tag matches our original intention before the
introduction of the color combinations.

[1]: https://github.com/odoo/odoo/commit/69190959ce8e08481be7ebdfefd314edf0c5dce1

opw-3524351

closes odoo/odoo#139155

X-original-commit: 733ac082fbaf47ce02bd82a66e342a99f1780ff4
Signed-off-by: Romain Derie (rde) <rde@odoo.com>
Signed-off-by: Benjamin Vray (bvr) <bvr@odoo.com>

addons/website_blog/static/src/scss/website_blog.scss

@@ -124,6 +124,10 @@ $o-wblog-loader-size: 50px;
     // Blog Post Page Cover
     // ==============================================
     .o_wblog_post_page_cover {
+        // "Latest Blog" Tag
+        .o_wblog_post_title > .h4 {
+            color: var(--o-cc3-btn-secondary-text);
+        }
 
         // Cover sizes
         // ==============================================