Fix some URLs whose sub-path is missing (#31289) (#31292)

Backport #31289 by wxiaoguang

Fix #31285

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

templates/admin/packages/list.tmpl

@@ -5,7 +5,7 @@
 			{{ctx.Locale.Tr "admin.packages.total_size" (FileSize .TotalBlobSize)}},
 			{{ctx.Locale.Tr "admin.packages.unreferenced_size" (FileSize .TotalUnreferencedBlobSize)}})
 			<div class="ui right">
-				<form method="post" action="/admin/packages/cleanup">
+				<form method="post" action="{{AppSubUrl}}/admin/packages/cleanup">
 					{{.CsrfTokenHtml}}
 					<button class="ui primary tiny button">{{ctx.Locale.Tr "admin.packages.cleanup"}}</button>
 				</form>

templates/devtest/fetch-action.tmpl

@@ -25,7 +25,7 @@
 				<div><label><input name="check" type="checkbox"> check</label></div>
 				<div><button name="btn">submit post</button></div>
 			</form>
-			<form method="post" action="/no-such-uri" class="form-fetch-action">
+			<form method="post" action="no-such-uri" class="form-fetch-action">
 				<div class="tw-py-8">bad action url</div>
 				<div><button name="btn">submit test</button></div>
 			</form>

templates/user/settings/applications.tmpl

@@ -75,7 +75,7 @@
 						{{ctx.Locale.Tr "settings.select_permissions"}}
 					</summary>
 					<p class="activity meta">
-						<i>{{ctx.Locale.Tr "settings.access_token_desc" (`href="/api/swagger" target="_blank"`|SafeHTML) (`href="https://docs.gitea.com/development/oauth2-provider#scopes" target="_blank"`|SafeHTML)}}</i>
+						<i>{{ctx.Locale.Tr "settings.access_token_desc" (HTMLFormat `href="%s/api/swagger" target="_blank"` AppSubUrl) (`href="https://docs.gitea.com/development/oauth2-provider#scopes" target="_blank"`|SafeHTML)}}</i>
 					</p>
 					<div class="scoped-access-token-mount">
 						<scoped-access-token-selector