cleanup locale function usage (#27227) (#27240)

Backport #27227 by @denyskon

Throughout the Gitea codebase, you can meet some weird constructions to
make `locale.Tr` work in subtemplates.
Since we now have `ctx.Locale.Tr` which solves that problem, clean up
various templates which pass `locale` through `dict` or use some weird
constructions like `$.root.locale`

Going on, it would be great to replace every case of `$.locale.Tr` and
`.locale.Tr` with `ctx.Locale.Tr`, but that needs to be done with
patience.

Co-authored-by: Denys Konovalov <kontakt@denyskon.de>

templates/repo/issue/view_content/comments_delete_time.tmpl

@@ -7,7 +7,7 @@
 						{{.ctxData.CsrfTokenHtml}}
 					</form>
 					<div class="header">{{.ctxData.locale.Tr "repo.issues.del_time"}}</div>
-					{{template "base/modal_actions_confirm" (dict "locale" .ctxData.locale)}}
+					{{template "base/modal_actions_confirm"}}
 				</div>
 				<button class="ui icon button compact mini issue-delete-time" data-id="{{.comment.Time.ID}}" data-tooltip-content="{{.ctxData.locale.Tr "repo.issues.del_time"}}">
 					{{svg "octicon-trash"}}