Enable gocritic equalFold and fix issues (#34952)

Continuation of https://github.com/go-gitea/gitea/pull/34678.

---------

Signed-off-by: silverwind <me@silverwind.io>

services/context/org.go

@@ -208,7 +208,7 @@ func OrgAssignment(opts OrgAssignmentOptions) func(ctx *Context) {
 		if len(teamName) > 0 {
 			teamExists := false
 			for _, team := range ctx.Org.Teams {
-				if team.LowerName == strings.ToLower(teamName) {
+				if strings.EqualFold(team.LowerName, teamName) {
 					teamExists = true
 					ctx.Org.Team = team
 					ctx.Org.IsTeamMember = true

services/context/repo.go

@@ -429,7 +429,7 @@ func RepoAssignment(ctx *Context) {
 	}
 
 	// Check if the user is the same as the repository owner
-	if ctx.IsSigned && ctx.Doer.LowerName == strings.ToLower(userName) {
+	if ctx.IsSigned && strings.EqualFold(ctx.Doer.LowerName, userName) {
 		ctx.Repo.Owner = ctx.Doer
 	} else {
 		ctx.Repo.Owner, err = user_model.GetUserByName(ctx, userName)

services/context/user.go

@@ -61,7 +61,7 @@ func UserAssignmentAPI() func(ctx *APIContext) {
 func userAssignment(ctx *Base, doer *user_model.User, errCb func(int, any)) (contextUser *user_model.User) {
 	username := ctx.PathParam("username")
 
-	if doer != nil && doer.LowerName == strings.ToLower(username) {
+	if doer != nil && strings.EqualFold(doer.LowerName, username) {
 		contextUser = doer
 	} else {
 		var err error