fix(ui): /settings/lfs/find 500 error

When in the repository settings, visiting

- `LFS` to `/{owner}/{repo}/settings/lfs`
- `Find pointer files` to `/{owner}/{repo}/settings/lfs/pointers`
- `Find commits` to `/{owner}/{repo}/settings/lfs/find?oid=...`

failed with an error 500 because of an incorrect evaluation of the
template.

Regression introduced by
cbf923e87b

A test is added to visit the page and guard against future
regressions.

Refs: https://codeberg.org/forgejo/forgejo/issues/3438

templates/repo/settings/lfs_file_find.tmpl

@@ -23,9 +23,9 @@
 								<span class="text grey">{{svg "octicon-git-branch"}}{{.BranchName}}</span>
 							</td>
 							<td>
-								{{if .ParentHashes}}
+								{{if .ParentIDs}}
 									{{ctx.Locale.Tr "repo.diff.parent"}}
-									{{range .ParentHashes}}
+									{{range .ParentIDs}}
 										<a class="ui primary sha label" href="{{$.RepoLink}}/commit/{{.String}}">{{ShortSha .String}}</a>
 									{{end}}
 								{{end}}