Create banner for KubeCon Japan (#6935)

Author: tiffany76

content/en/announcements/kubecon-japan.md

@@ -0,0 +1,14 @@
+---
+title: KubeCon + CloudNativeCon Japan 2025
+linkTitle: KubeCon Japan 2025
+date: 2025-05-20
+expiryDate: 2025-06-17
+---
+
+<i class="fas fa-bullhorn"></i> [**{{% param title %}}**][LF],
+**<span class="text-nowrap">June 16 - 17,</span> Tokyo**
+<span class="d-none d-md-inline"><br></span> Come collaborate, learn, and
+share<span class="d-none d-sm-inline"> with the Cloud Native community</span>!
+
+[LF]:
+  https://events.linuxfoundation.org/kubecon-cloudnativecon-japan/register/?utm_source=opentelemetry&utm_medium=all&utm_campaign=KubeCon-Japan-2025&utm_content=slim-banner

static/refcache.json

@@ -2215,6 +2215,10 @@
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     "LastSeen": "2025-01-15T13:17:55.721664-05:00"
   },
+  "https://events.linuxfoundation.org/kubecon-cloudnativecon-japan/register/": {
+    "StatusCode": 206,
+    "LastSeen": "2025-05-20T15:48:48.226856798-07:00"
+  },
   "https://events.linuxfoundation.org/kubecon-cloudnativecon-north-america/": {
     "StatusCode": 200,
     "LastSeen": "2025-01-13T12:11:00.520901-05:00"