smplayer: 18.4.0 -> 18.5.0 (#41040)

Semi-automatic update generated by https://github.com/ryantm/nixpkgs-update tools.

This update was made based on information from https://repology.org/metapackage/smplayer/versions.

These checks were done:

- built on NixOS
- Warning: no invocation of /nix/store/mll3p02g4sfglbg8d7z54y748z16rhwr-smplayer-18.5.0/bin/smplayer had a zero exit code or showed the expected version
- Warning: no invocation of /nix/store/mll3p02g4sfglbg8d7z54y748z16rhwr-smplayer-18.5.0/bin/simple_web_server had a zero exit code or showed the expected version
- 0 of 2 passed binary check by having a zero exit code.
- 0 of 2 passed binary check by having the new version present in output.
- found 18.5.0 with grep in /nix/store/mll3p02g4sfglbg8d7z54y748z16rhwr-smplayer-18.5.0
- directory tree listing: https://gist.github.com/68e3b40c30899a9dbba0225f52760bda
- du listing: https://gist.github.com/e7152199c8f96f4ba4fdcc614d54f3d8