Title can be empty when creating tag only (#23917) (#23961)

Backport #23917 by @Zettat123

Fixes #23809

Make the title not required. If the title is empty when creating release
(not tag), an error message will be displayed.

![image](https://user-images.githubusercontent.com/15528715/229761056-c52e338b-5f25-4d7d-bb44-2cb0304abcee.png)

Co-authored-by: Zettat123 <zettat123@gmail.com>

templates/repo/release/new.tmpl

@@ -42,7 +42,7 @@
 			<div class="eleven wide column">
 				<div class="field {{if .Err_Title}}error{{end}}">
 					<label>{{.locale.Tr "repo.release.title"}}</label>
-					<input name="title" placeholder="{{.locale.Tr "repo.release.title"}}" value="{{.title}}" autofocus required maxlength="255">
+					<input name="title" placeholder="{{.locale.Tr "repo.release.title"}}" value="{{.title}}" autofocus maxlength="255">
 				</div>
 				<div class="field content-editor">
 					<label>{{.locale.Tr "repo.release.content"}}</label>