Failed authentications are logged to level Warning (#32016)

PR for issue #31968 
Replaces PR #31983 to comply with gitea's error definition

Failed authentications are now logged to level `Warning` instead of
`Info`.

routers/web/auth/auth.go

@@ -228,12 +228,12 @@ func SignInPost(ctx *context.Context) {
 	if err != nil {
 		if errors.Is(err, util.ErrNotExist) || errors.Is(err, util.ErrInvalidArgument) {
 			ctx.RenderWithErr(ctx.Tr("form.username_password_incorrect"), tplSignIn, &form)
-			log.Info("Failed authentication attempt for %s from %s: %v", form.UserName, ctx.RemoteAddr(), err)
+			log.Warn("Failed authentication attempt for %s from %s: %v", form.UserName, ctx.RemoteAddr(), err)
 		} else if user_model.IsErrEmailAlreadyUsed(err) {
 			ctx.RenderWithErr(ctx.Tr("form.email_been_used"), tplSignIn, &form)
-			log.Info("Failed authentication attempt for %s from %s: %v", form.UserName, ctx.RemoteAddr(), err)
+			log.Warn("Failed authentication attempt for %s from %s: %v", form.UserName, ctx.RemoteAddr(), err)
 		} else if user_model.IsErrUserProhibitLogin(err) {
-			log.Info("Failed authentication attempt for %s from %s: %v", form.UserName, ctx.RemoteAddr(), err)
+			log.Warn("Failed authentication attempt for %s from %s: %v", form.UserName, ctx.RemoteAddr(), err)
 			ctx.Data["Title"] = ctx.Tr("auth.prohibit_login")
 			ctx.HTML(http.StatusOK, "user/auth/prohibit_login")
 		} else if user_model.IsErrUserInactive(err) {
@@ -241,7 +241,7 @@ func SignInPost(ctx *context.Context) {
 				ctx.Data["Title"] = ctx.Tr("auth.active_your_account")
 				ctx.HTML(http.StatusOK, TplActivate)
 			} else {
-				log.Info("Failed authentication attempt for %s from %s: %v", form.UserName, ctx.RemoteAddr(), err)
+				log.Warn("Failed authentication attempt for %s from %s: %v", form.UserName, ctx.RemoteAddr(), err)
 				ctx.Data["Title"] = ctx.Tr("auth.prohibit_login")
 				ctx.HTML(http.StatusOK, "user/auth/prohibit_login")
 			}