Remove deprecated query condition in ListReleases

[lng2020]

close #24057
call stack:

gitea/routers/api/v1/repo/release.go

Line 154 in 25faee3

if listOptions.PageSize == 0 && ctx.FormInt("per_page") != 0 {

gitea/routers/api/v1/utils/page.go

Lines 13 to 18 in ec1feed

	func GetListOptions(ctx *context.APIContext) db.ListOptions {
	return db.ListOptions{
	Page: ctx.FormInt("page"),
	PageSize: convert.ToCorrectPageSize(ctx.FormInt("limit")),
	}
	}

gitea/services/convert/utils.go

Lines 15 to 22 in ec1feed

	func ToCorrectPageSize(size int) int {
	if size <= 0 {
	size = setting.API.DefaultPagingNum
	} else if size > setting.API.MaxResponseItems {
	size = setting.API.MaxResponseItems
	}
	return size
	}

⚠️ Breaking ⚠️ (though it's not caused by this PR)

Do not use per_page to specify pagination; use limit instead

[lunny]

Maybe that PR should not be considered as breaking because it kept the compatible as before.

[lng2020]

After doing some digging, I found this one: https://github.com/go-gitea/gitea/pull/16175/files#diff-91fd5bc00cb24aac69be1c0504b0765185c9cf69dfd561e50b1de6c808228ca2L103 is accidentally caused the per_page useless, which cause the breaking. Before that, although per_page is deprecated, the user can still use this condition.
So there are two options:

1. remove listOptions.PageSize == 0 to let per_page work again, although it's been deprecated and useless for a long time.
2. Remove the per_page condition and label it breaking, although it's not the real breaking reason. Just as this PR does.