libsForQt5.bismuth: Fix generated JS

As of 5789287a95, esbuild was updated to
0.18.5 which introduced a new transpilation called "Static fields with
assign semantics now use static blocks if possible"
(https://github.com/evanw/esbuild/blob/v0.18.5/CHANGELOG.md).  This
causes generation of JavaScript code that is incompatible with KWin's
JavaScript engine, resulting in errors loading Bismuth.

This update uses esbuild's `--target` option to generate compatible
output code.

pkgs/desktops/plasma-5/3rdparty/addons/bismuth/0001-esbuild-config.patch

@@ -0,0 +1,13 @@
+diff --git a/src/kwinscript/CMakeLists.txt b/src/kwinscript/CMakeLists.txt
+index 9e2f7054..ed607027 100644
+--- a/src/kwinscript/CMakeLists.txt
++++ b/src/kwinscript/CMakeLists.txt
+@@ -39,7 +39,7 @@ endif()
+ set(ESBUILD_COMMAND
+     "esbuild" "--bundle" "${CMAKE_CURRENT_SOURCE_DIR}/index.ts"
+     "--outfile=${CMAKE_CURRENT_BINARY_DIR}/bismuth/contents/code/index.mjs"
+-    "--format=esm" "--platform=neutral")
++    "--format=esm" "--platform=neutral" "--target=es6")
+ if(USE_NPM)
+   list(PREPEND ESBUILD_COMMAND "npx")
+ endif()

pkgs/desktops/plasma-5/3rdparty/addons/bismuth/default.nix

@@ -21,6 +21,10 @@ mkDerivation rec {
     sha256 = "sha256-c13OFEw6E/I8j/mqeLnuc9Chi6pc3+AgwAMPpCzh974=";
   };
 
+  patches = [
+    ./0001-esbuild-config.patch
+  ];
+
   cmakeFlags = [
     "-DUSE_TSC=OFF"
     "-DUSE_NPM=OFF"