[GITEA] Add download URL for executable files

- Consider executable files as a valid case when returning a downloadURL
for them. They are just regular files with the difference being the
executable permission bit being set.
- Not integration testing as it's not possible without adding adjusting
the existing repositories to have a executable file.
- Resolves https://codeberg.org/forgejo/forgejo/issues/1825

(cherry picked from commit ca32891d54)

services/repository/files/content.go

@@ -219,7 +219,7 @@ func GetContents(ctx context.Context, repo *repo_model.Repository, treePath, ref
 		}
 	}
 	// Handle links
-	if entry.IsRegular() || entry.IsLink() {
+	if entry.IsRegular() || entry.IsLink() || entry.IsExecutable() {
 		downloadURL, err := url.Parse(repo.HTMLURL() + "/raw/" + url.PathEscape(string(refType)) + "/" + util.PathEscapeSegments(ref) + "/" + util.PathEscapeSegments(treePath))
 		if err != nil {
 			return nil, err