zed-editor: fix remote server executable name

The remote server executable in the zed-editor package has a '+stable'
appended at the end now. This uses the remoteServerExecutableName
attribute from the zed-editor package instead of guessing.

modules/programs/zed-editor.nix

@@ -246,8 +246,8 @@ in
 
     home.file = mkIf (cfg.installRemoteServer && (cfg.package ? remote_server)) (
       let
-        inherit (cfg.package) version remote_server;
-        binaryName = "zed-remote-server-stable-${version}";
+        inherit (cfg.package) remote_server;
+        binaryName = cfg.package.remoteServerExecutableName;
       in
       {
         ".zed_server/${binaryName}".source = lib.getExe' remote_server binaryName;

tests/modules/programs/zed-editor/install-remote-server.nix

@@ -1,5 +1,8 @@
 { config, ... }:
 
+let
+  executableName = "zed-remote-server-stable-57+stable";
+in
 {
   programs.zed-editor = {
     enable = true;
@@ -7,14 +10,15 @@
       remote_server = config.lib.test.mkStubPackage {
         buildScript = ''
           mkdir -p $out/bin
-          touch $out/bin/zed-remote-server-stable-57
+          touch $out/bin/${executableName}
         '';
       };
+      remoteServerExecutableName = executableName;
     };
     installRemoteServer = true;
   };
 
   nmt.script = ''
-    assertFileExists "home-files/.zed_server/zed-remote-server-stable-57"
+    assertFileExists "home-files/.zed_server/${executableName}"
   '';
 }