Update metainfo with v4.5 info

org.photoqt.PhotoQt.metainfo.xml

@@ -104,6 +104,14 @@
         <content_attribute id="money-gambling">none</content_attribute>
     </content_rating>
     <releases>
+        <release version="4.5" date="2024-05-13">
+            <description>
+                PhotoQt v4.5 brings a few new additions, but mostly focuses on bug fixes, improvements, and generally a more polished user experience.
+            </description>
+            <url>
+                https://photoqt.org/news/photoqt-4.5
+            </url>
+        </release>
         <release version="4.4" date="2024-04-04">
             <description>
                 PhotoQt v4.4 brings a whole range of exciting new features, from support for color profiles, to accent colors, lossless zoom for vector graphics, and so much more - there is something for everybody.