pyradio: Disable update check

pyradio checks for new releases every 10 days and offers the user to
self-update:

```console
$ pyradio --update
Released version   :  0.9.3.3
Installed version  :  0.9.3.1
Updating PyRadio...
Using directory: "/tmp/tmp-pyradio"
Downloading PyRadio source code...
  url: "https://github.com/coderholic/pyradio/archive/0.9.3.3.zip"
  filename: "/tmp/tmp-pyradio/pyradio-0.9.3.3.zip"
^CError: Failed to download PyRadio source code..
```

This functionality can be disabled by setting the `distro` configuration
parameter to anything different than `None`. With such patch applied, it
will now refuse to self-update:

```console
$ pyradio --update
PyRadio has been installed using either pip or your distribution's
package manager. Please use that to update it.
```

Co-authored-by: Guilhem Saurel <guilhem.saurel@laas.fr>

pkgs/applications/audio/pyradio/default.nix

@@ -28,6 +28,12 @@ python3Packages.buildPythonApplication rec {
     rich
   ];
 
+  postPatch = ''
+    # Disable update check
+    substituteInPlace pyradio/config \
+      --replace-fail "distro = None" "distro = NixOS"
+  '';
+
   checkPhase = ''
     $out/bin/pyradio --help
   '';