Fix landing page hero bg (#373)

Hey @madolson here is a fix to the "sharp line" in the new hero image
changes

<img width="1728" height="1040" alt="Screenshot 2025-10-02 at 8 18
09 AM"
src="https://github.com/user-attachments/assets/7d6dd4f9-5b2b-48d2-94c2-41071ade2c16"
/>

---------

Signed-off-by: Daniel Phillips <[email protected]>

Author: phiro56

sass/_valkey.scss

@@ -1602,6 +1602,13 @@ html.banner-hidden .banner {
   overflow: hidden;
   padding: 8rem 2rem;
 
+  &::after {
+    content: "";
+    position: absolute; inset: 0;
+    background-image: linear-gradient(to bottom, rgba(48, 24, 110, 0), rgba(48, 24, 110, 100));
+    pointer-events: none;
+  }
+
   @include respond-min(768px) {
     padding: 10rem 2rem;