electron_34-bin: mark as insecure because it's EOL; electron-source.electron_34: remove as it's EOL (#419903)

pkgs/development/tools/electron/binary/generic.nix

@@ -58,7 +58,7 @@ let
     ];
     sourceProvenance = with sourceTypes; [ binaryNativeCode ];
     # https://www.electronjs.org/docs/latest/tutorial/electron-timelines
-    knownVulnerabilities = optional (versionOlder version "34.0.0") "Electron version ${version} is EOL";
+    knownVulnerabilities = optional (versionOlder version "35.0.0") "Electron version ${version} is EOL";
   };
 
   fetcher =

pkgs/top-level/all-packages.nix

@@ -6847,11 +6847,7 @@ with pkgs;
     ;
 
   electron_33 = electron_33-bin;
-  electron_34 =
-    if lib.meta.availableOn stdenv.hostPlatform electron-source.electron_34 then
-      electron-source.electron_34
-    else
-      electron_34-bin;
+  electron_34 = electron_34-bin;
   electron_35 =
     if lib.meta.availableOn stdenv.hostPlatform electron-source.electron_35 then
       electron-source.electron_35