[web] Remove layout slot no longer needed

At #781, the Sidebar was created
directly from the Layout by using a slot for teleporting its content
from outside. That was needed because the Layout was moved to a
provider. Later, #796 restored the
previous behavior of mounting both, the Sidebar and the Layout, from
src/App.jsx instead of having "content components" in the providers,
which was  weird if not wrong.

However, the slot created for the Sidebar content was not removed and it
was creating an empty div node between the sidebar and the main content.
Although it wasn't producing any visible side effect in the UI, it has
been removed since it is actually no longer needed.

web/src/components/layout/Layout.jsx

@@ -30,7 +30,6 @@ const HeaderActions = createTeleporter();
 const HeaderIcon = createTeleporter();
 const FooterActions = createTeleporter();
 const FooterInfoArea = createTeleporter();
-const Sidebar = createTeleporter();
 
 /**
  *
@@ -65,35 +64,32 @@ const Sidebar = createTeleporter();
  */
 function Layout({ children }) {
   return (
-    <>
-      <Sidebar.Target as="div" />
-      <div id="agama-main-wrapper" className="wrapper shadow">
-        <header className="split justify-between bottom-shadow">
-          <h1 className="split">
-            <HeaderIcon.Target as="span" />
-            <PageTitle.Target as="span" />
-          </h1>
-
-          <div className="split">
-            <PageActions.Target as="div" />
-            <HeaderActions.Target as="div" />
-          </div>
-
-        </header>
-
-        <main className="stack">
-          {children}
-        </main>
-
-        <footer className="split justify-between top-shadow" data-state="reversed">
-          <FooterActions.Target
-            role="navigation"
-            aria-label="Installer Actions"
-          />
-          <img src={logoUrl} alt="Logo of SUSE" />
-        </footer>
-      </div>
-    </>
+    <div id="agama-main-wrapper" className="wrapper shadow">
+      <header className="split justify-between bottom-shadow">
+        <h1 className="split">
+          <HeaderIcon.Target as="span" />
+          <PageTitle.Target as="span" />
+        </h1>
+
+        <div className="split">
+          <PageActions.Target as="div" />
+          <HeaderActions.Target as="div" />
+        </div>
+
+      </header>
+
+      <main className="stack">
+        {children}
+      </main>
+
+      <footer className="split justify-between top-shadow" data-state="reversed">
+        <FooterActions.Target
+          role="navigation"
+          aria-label="Installer Actions"
+        />
+        <img src={logoUrl} alt="Logo of SUSE" />
+      </footer>
+    </div>
   );
 }
 
@@ -171,8 +167,6 @@ const MainActions = FooterActions.Source;
  */
 const AdditionalInfo = FooterInfoArea.Source;
 
-const SidebarArea = Sidebar.Source;
-
 export {
   Layout as default,
   Title,
@@ -181,5 +175,4 @@ export {
   PageOptions,
   MainActions,
   AdditionalInfo,
-  SidebarArea
 };