Release 8.4.0 (#2431)

* Release 8.4.0

* Update meson.build

* Update appcenter.metainfo.xml.in

Author: danirabbit

data/appcenter.metainfo.xml.in

@@ -65,7 +65,7 @@
   <update_contact>contact_at_elementary.io</update_contact>
 
   <releases>
-    <release version="8.4.0" date="2026-03-16">
+    <release version="8.4.0" date="2026-03-31">
       <description>
         <p>Other Improvements:</p>
         <ul>

meson.build

@@ -1,7 +1,7 @@
 project(
     'io.elementary.appcenter',
     'vala', 'c',
-    version: '8.3.2',
+    version: '8.4.0',
     meson_version: '>=0.57.0'
 )