chore(main): release 3.13.0

:robot: I have created a release *beep* *boop* --- ## [3.13.0](https://github.com/rest-nvim/rest.nvim/compare/v3.12.0...v3.13.0) (2025-06-11) ### Features * remove $dotenv tags from variables ([#546](https://github.com/rest-nvim/rest.nvim/issues/546)) ([5e7cc25](https://github.com/rest-nvim/rest.nvim/commit/5e7cc25b9e10674cc8d0773a17d947a8ef537ae8)) --- This PR was generated with [Release Please](https://github.com/googleapis/release-please). See [documentation](https://github.com/googleapis/release-please#release-please).