Add sold out note for silver+

Author: hypha

src/content/pages/sponsorship/sponsor.mdx

@@ -51,6 +51,11 @@ supporting the Python community is accessible for organisations of all sizes.
 <Button class="m-2" url="https://drive.google.com/file/d/1AGvH0w3fMLRvaNDa5VPCs78rtc4MnL6h/view?usp=sharing">Full Sponsorship Opportunities (PDF)</Button>
 <Button class="m-2" url="https://forms.gle/T8da5sQbKn6BFsxH7">Sign up now!</Button>
 
+<Note>
+<span className="block text-xl font-semibold mb-2">**Platinum, Gold and Silver packages are now fully booked**.</span>
+<span>If you're interested in sponsoring, please fill out the signup form above or contact us at [email protected]. We’d love to explore options with you!</span>
+</Note>
+
 
 <SponsorTiers signupLink="https://forms.gle/T8da5sQbKn6BFsxH7" />