docs banner update v1.2.0 (#974)

Author: karifabri

website/docusaurus.config.ts

@@ -92,7 +92,7 @@ const config: Config = {
     // Replace with your project's social card
     image: 'img/og/spiceai.png',
     announcementBar: {
-      content: '<a href="/blog/releases/v1.1.2">Spice.ai OSS v1.1.2</a> is now available! 🚀',
+      content: '<a href="/blog/releases/v1.2.0">Spice.ai OSS v1.2.0</a> is now available! 🚀',
       backgroundColor: 'var(--announcement-bar-bg)',
       textColor: 'var(--announcement-bar-text)',
       isCloseable: true