Update release notes

Author: jamiebuilds-signal

_locales/en/messages.json

@@ -9672,5 +9672,13 @@
   "icu:WhatsNew__7.77-2": {
     "messageformat": "This update also includes a bugfix for an issue that prevented link previews from being generated when the message also included emoji characters. Thanks, <elias6></elias6>",
     "description": " Release notes for 7.77 release"
+  },
+  "icu:WhatsNew__7.78-1": {
+    "messageformat": "This update improves accessibility for screen reader users by skipping repeated timestamp announcements when new messages arrive in a thread.",
+    "description": " Release notes for 7.78 release"
+  },
+  "icu:WhatsNew__7.78-2": {
+    "messageformat": "We also fixed a bug that could prevent notifications from appearing on Windows.",
+    "description": " Release notes for 7.78 release"
   }
 }

ts/components/WhatsNewModal.dom.tsx

@@ -48,14 +48,8 @@ export function WhatsNewModal({
     date: new Date(window.getBuildCreation?.() || Date.now()),
     version: window.getVersion?.(),
     features: [
-      <I18n i18n={i18n} id="icu:WhatsNew__7.77-1" />,
-      <I18n
-        i18n={i18n}
-        id="icu:WhatsNew__7.77-2"
-        components={{
-          elias6: Elias6,
-        }}
-      />,
+      <I18n i18n={i18n} id="icu:WhatsNew__7.78-1" />,
+      <I18n i18n={i18n} id="icu:WhatsNew__7.78-2" />,
     ],
   };