chromium: Install vk_swiftshader_icd.json

This should be required for Vulkan support via SwiftShader but I wasn't
able to test/confirm it yet (according to strace Chromium never tried to
load that file). The relevant flags for using Chromium with SwiftShader
are documented at [0] and SwiftShader's ANGLE documentation [1] mentions
the relevant files. See also [2], [3], and [4] for more details.

[0]: https://source.chromium.org/chromium/chromium/src/+/master:docs/gpu/swiftshader.md;drc=046f987e020baba45ffb3061b3ee3d960d6ce981
[1]: 2413491078/docs/ANGLE.md
[2]: 2413491078/README.md
[3]: ca9efe3f1c/docs/LoaderInterfaceArchitecture.md
[4]: https://bugs.archlinux.org/task/72652

pkgs/applications/networking/browsers/chromium/browser.nix

@@ -17,6 +17,7 @@ mkChromiumDerivation (base: rec {
   installPhase = ''
     mkdir -p "$libExecPath"
     cp -v "$buildPath/"*.so "$buildPath/"*.pak "$buildPath/"*.bin "$libExecPath/"
+    cp -v "$buildPath/vk_swiftshader_icd.json" "$libExecPath/"
     cp -v "$buildPath/icudtl.dat" "$libExecPath/"
     cp -vLR "$buildPath/locales" "$buildPath/resources" "$libExecPath/"
     cp -v "$buildPath/chrome_crashpad_handler" "$libExecPath/"