[FIX] website_slides: make text readable in white navigation bar

The navigation bar inside the Courses main page and the courses list
are forced to white with an inline style.
When a dark palette is used it makes the text color white as well.
Because of this the texts in those navigation bars cannot be read
anymore.

This commit removes the forced white background so that colors can
automatically adapt to the palette.

Steps to reproduce:
- Pick a dark palette.
- Go to the "Courses" page.
=> "All courses" and its icon were not visible anymore.

task-2855511

closes odoo/odoo#97148

X-original-commit: 852acad7585fa884f365dd2fc10348446d56d4e9
Related: odoo/enterprise#29995
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>

addons/website_slides/views/website_slides_templates_homepage.xml

@@ -22,7 +22,7 @@
             </section>
             </div>
             <div class="container mt16 o_wslides_home_nav position-relative">
-                <nav class="navbar navbar-expand-lg navbar-light shadow-sm" style="background: white!important">
+                <nav class="navbar navbar-expand-lg navbar-light shadow-sm">
                     <t t-call="website.website_search_box_input">
                         <t t-set="_form_classes" t-valuef="form-inline o_wslides_nav_navbar_right order-lg-3"/>
                         <t t-set="search_type" t-valuef="slides"/>
@@ -193,7 +193,7 @@
             </div>
             <div class="container mt16 o_wslides_home_nav position-relative">
                 <!-- Navbar dynamically composed using displayed channel tag groups. -->
-                <nav class="navbar navbar-expand-md navbar-light shadow-sm ps-0" style="background: white!important">
+                <nav class="navbar navbar-expand-md navbar-light shadow-sm ps-0">
                     <div class="navbar-nav border-end">
                         <a class="nav-link nav-item px-3" href="/slides"><i class="fa fa-chevron-left"/></a>
                     </div>