Fix: Allow org team names of length 255 in create team form (#31564) (#31603)

Backport #31564 by @tobiasbp

Gitea 1.22.1 was supposed to allow for team names of length 255 (up from
30) after the following PR was merged in:
https://github.com/go-gitea/gitea/pull/31410. However, the length of
team names was still limited to 30 as described in this issue:
https://github.com/go-gitea/gitea/issues/31554.

One more change to _gitea_ needs to be made to allow for the longer team
names, as there is a 30 character limit here:
https://github.com/go-gitea/gitea/blob/2c92c7c5226e29636a1d47a277130f477fa2037b/services/forms/org.go#L65

This PR changes that value to 255.

Co-authored-by: Tobias Balle-Petersen <tobias.petersen@unity3d.com>

services/forms/org.go

@@ -62,7 +62,7 @@ func (f *UpdateOrgSettingForm) Validate(req *http.Request, errs binding.Errors)
 
 // CreateTeamForm form for creating team
 type CreateTeamForm struct {
-	TeamName         string `binding:"Required;AlphaDashDot;MaxSize(30)"`
+	TeamName         string `binding:"Required;AlphaDashDot;MaxSize(255)"`
 	Description      string `binding:"MaxSize(255)"`
 	Permission       string
 	RepoAccess       string