Update Slack invite link in header.html (#237)

diff --git a/iceberg-theme/layouts/partials/header.html b/iceberg-theme/layouts/partials/header.html
index c71d42c..6ced88c 100644
--- a/iceberg-theme/layouts/partials/header.html
+++ b/iceberg-theme/layouts/partials/header.html
@@ -67,7 +67,7 @@
                         </a>
                     </div>
                     <div class="topnav-page-selection">
-                        <a href="https://join.slack.com/t/apache-iceberg/shared_invite/zt-1oj35f7yc-wuTEhvkiqjGLje83B7rG8A" target="_blank">
+                        <a href="https://join.slack.com/t/apache-iceberg/shared_invite/zt-1uva9gyp1-TrLQl7o~nZ5PsTVgl6uoEQ" target="_blank">
                             <img src="{{ $.Site.BaseURL }}/img/Slack_Mark_Web.png" target="_blank" class="top-navbar-logo"/>
                         </a>
                     </div>