conf: use full domain name for the og images (graphql#1517)

Author: beerose

src/components/Conf/Seo/index.tsx

@@ -32,7 +32,6 @@ export default function SeoConf(props: {
       <meta property="og:title" content={title} />
       <meta property="og:description" content={description} />
       <meta property="og:image" content={image} />
-      <meta property="twitter:image" content={image} />
       <meta
         property="og:image:alt"
         content="GraphQLConf 2023 hosted by the GraphQL Foundation. September 19-21, 2023. San Francisco Bay Area, California"

src/templates/event.tsx

@@ -208,7 +208,7 @@ export function Head({
         title={`${event.name} | GraphQLConf 2023`}
         description={event.description}
         ogImage={{
-          url: `/img/__og-image/${event.id}.png`,
+          url: `https://graphql.org/img/__og-image/${event.id}.png`,
           width: 1200,
           height: 630,
         }}