Fix Permission in API returned repository struct (#25388)

The old code generates `structs.Repository.Permissions` with only
`access.Permission.AccessMode`, however, it should check the units too,
or the value could be incorrect. For example,
`structs.Repository.Permissions.Push` could be false even the doer has
write access to code unit.

Should fix
https://github.com/renovatebot/renovate/issues/14059#issuecomment-1047961128
(Not reported by it, I just found it when I was looking into this bug)

---

Review tips:

The major changes are
- `modules/structs/repo.go`
https://github.com/go-gitea/gitea/pull/25388/files#diff-870406f6857117f8b03611c43fca0ab9ed6d6e76a2d0069a7c1f17e8fa9092f7
- `services/convert/repository.go`
https://github.com/go-gitea/gitea/pull/25388/files#diff-7736f6d2ae894c9edb7729a80ab89aa183b888a26a811a0c1fdebd18726a7101

And other changes are passive.

routers/api/v1/repo/key.go

@@ -13,6 +13,7 @@ import (
 	asymkey_model "code.gitea.io/gitea/models/asymkey"
 	"code.gitea.io/gitea/models/db"
 	"code.gitea.io/gitea/models/perm"
+	access_model "code.gitea.io/gitea/models/perm/access"
 	repo_model "code.gitea.io/gitea/models/repo"
 	"code.gitea.io/gitea/modules/context"
 	"code.gitea.io/gitea/modules/setting"
@@ -27,13 +28,13 @@ import (
 func appendPrivateInformation(ctx stdCtx.Context, apiKey *api.DeployKey, key *asymkey_model.DeployKey, repository *repo_model.Repository) (*api.DeployKey, error) {
 	apiKey.ReadOnly = key.Mode == perm.AccessModeRead
 	if repository.ID == key.RepoID {
-		apiKey.Repository = convert.ToRepo(ctx, repository, key.Mode)
+		apiKey.Repository = convert.ToRepo(ctx, repository, access_model.Permission{AccessMode: key.Mode})
 	} else {
 		repo, err := repo_model.GetRepositoryByID(ctx, key.RepoID)
 		if err != nil {
 			return apiKey, err
 		}
-		apiKey.Repository = convert.ToRepo(ctx, repo, key.Mode)
+		apiKey.Repository = convert.ToRepo(ctx, repo, access_model.Permission{AccessMode: key.Mode})
 	}
 	return apiKey, nil
 }