Add "Updated" column for admin repositories list (#24429)

- Closes #12454

# Before

![image](https://user-images.githubusercontent.com/20454870/235314351-82f5a414-7827-4029-8779-a837283a5a05.png)
# After

![image](https://user-images.githubusercontent.com/20454870/235314376-ccf4bb95-6823-4fce-9b9a-a23da2351769.png)

Signed-off-by: Yarden Shoham <git@yardenshoham.com>

templates/admin/repo/list.tmpl

@@ -33,6 +33,7 @@
 							{{.locale.Tr "admin.repos.size"}}
 							{{SortArrow "size" "reversesize" $.SortType false}}
 						</th>
+						<th>{{.locale.Tr "admin.auths.updated"}}</th>
 						<th>{{.locale.Tr "admin.users.created"}}</th>
 						<th>{{.locale.Tr "admin.notices.op"}}</th>
 					</tr>
@@ -80,6 +81,7 @@
 							<td>{{.NumForks}}</td>
 							<td>{{.NumIssues}}</td>
 							<td>{{FileSize .Size}}</td>
+							<td>{{DateTime "short" .UpdatedUnix}}</td>
 							<td>{{DateTime "short" .CreatedUnix}}</td>
 							<td><a class="delete-button" href="" data-url="{{$.Link}}/delete?page={{$.Page.Paginater.Current}}&sort={{$.SortType}}" data-id="{{.ID}}" data-name="{{.Name}}">{{svg "octicon-trash"}}</a></td>
 						</tr>