Revert #6733 to avoid breaking changes for extensions (#6821)

This reverts commit 4af8fbaa34.

Signed-off-by: Alex Andreev <alex.andreev.email@gmail.com>

Signed-off-by: Alex Andreev <alex.andreev.email@gmail.com>

src/renderer/components/cluster-manager/cluster-manager.scss

@@ -27,7 +27,7 @@
   }
 
   .error {
-    z-index: var(--z-index-base);
+    z-index: 1;
   }
 
   #lens-views {

src/renderer/components/cluster-manager/cluster-status.module.scss

@@ -5,6 +5,7 @@
   min-width: 350px;
   margin: auto;
   text-align: center;
+  z-index: 1;
   background: var(--mainBackground);
   width: 100%;
   height: 100%;