fix(electron): add icon for AppImage build (#6257)

1. the icon is fixed in `/Applications`: https://github.com/toeverything/electron-forge-maker-appimage/commit/128b8c22f9b2e088ce4f88057749b0a8cd55ca98#diff-a694a3e854f53b066e34ec310e05bd18b4944c016455f6963f54a351784d5fa6L91
2. the App's icon MUST be 64x64 png and set via `setIcon`

![image](https://github.com/toeverything/AFFiNE/assets/584378/bbce0007-066b-413f-a85a-193acbbe5c13)

packages/frontend/electron/scripts/make-env.ts

@@ -20,6 +20,11 @@ const icoPath = path.join(
     : './resources/icons/icon.ico'
 );
 
+const iconX64PngPath = path.join(
+  ROOT,
+  `./resources/icons/icon_${buildType}_64x64.png`
+);
+
 const icnsPath = path.join(
   ROOT,
   !stableBuild
@@ -46,6 +51,7 @@ export {
   icnsPath,
   iconPngPath,
   iconUrl,
+  iconX64PngPath,
   icoPath,
   platform,
   productName,