Since actions can specify the download source via a url prefix. The prefix may contain some sensitive information that needs to be stored in secrets or variable context, so we need to interpolate the expression value for`uses` firstly.
Reviewed-on: https://gitea.com/gitea/act/pulls/75
Co-authored-by: sillyguodong <gedong_1994@163.com>
Co-committed-by: sillyguodong <gedong_1994@163.com>