Fix template function DateTime (#24317)

Before, 500 error


![image](https://user-images.githubusercontent.com/2114189/234170176-403ffd1b-ec27-42be-bff9-86184dc8d74d.png)

templates/package/shared/cleanup_rules/preview.tmpl

@@ -22,7 +22,7 @@
 					<td><a href="{{.FullWebLink}}">{{.Version.Version}}</a></td>
 					<td><a href="{{.Creator.HomeLink}}">{{.Creator.Name}}</a></td>
 					<td>{{FileSize .CalculateBlobSize}}</td>
-					<td>{{DateTime "short" .Version.CreatedUnix.FormatLong .Version.CreatedUnix.FormatShort}}</td>
+					<td>{{DateTime "short" .Version.CreatedUnix}}</td>
 				</tr>
 			{{else}}
 				<tr>

templates/package/view.tmpl

@@ -86,7 +86,7 @@
 							{{range .LatestVersions}}
 								<div class="item gt-df">
 									<a class="gt-f1" href="{{$.PackageDescriptor.PackageWebLink}}/{{PathEscape .LowerVersion}}">{{.Version}}</a>
-									<span class="text small">{{DateTime "short" (.CreatedUnix.FormatDate) (.CreatedUnix.FormatDate)}}</span>
+									<span class="text small">{{DateTime "short" .CreatedUnix}}</span>
 								</div>
 							{{end}}
 							</div>