Update esbuild.js

Turns out I was quite naive about just excluding graphql-config.  The extension worked under the Test Runner, but not when bundled and installed.

This change actually does work, even when the plugin is bundled and installed separately.  It uses the technique outlined in evanw/esbuild#2441

Author: craig-riecke

packages/vscode-graphql-execution/esbuild.js

@@ -46,10 +46,13 @@ build({
     'atpl',
     'liquor',
     'twig',
-    'graphql-config',
   ],
   format: 'cjs',
   sourcemap: true,
+  define: { 'import.meta.url': '_importMetaUrl' },
+  banner: {
+    js: "const _importMetaUrl=require('url').pathToFileURL(__filename)",
+  },
 })
   .then(({ errors, warnings }) => {
     if (warnings.length) {