Load version when used.

Only load the package in the rare case of showing the version. This is
somewhat dependent on the current behavior of commander and how it uses
the version parameter.

bin/jsonld.js

@@ -8,19 +8,28 @@
  * Copyright (c) 2013-2022 Digital Bazaar, Inc.
  * All rights reserved.
  */
+import {fileURLToPath} from 'node:url';
 import https from 'node:https';
 import {inspect} from 'node:util';
 import jsonld from 'jsonld';
 import {jsonldRequest} from 'jsonld-request';
 import path from 'node:path';
 import {program} from 'commander';
-
-import {fileURLToPath} from 'node:url';
-const __dirname = path.dirname(fileURLToPath(import.meta.url));
-
 import {readFileSync} from 'node:fs';
-const version =
-  JSON.parse(readFileSync(path.join(__dirname, '..', 'package.json'))).version;
+
+const version = {
+  value: undefined,
+  toString() {
+    // load version when used
+    if(this.value === undefined) {
+      const __dirname = path.dirname(fileURLToPath(import.meta.url));
+      const pkg =
+        JSON.parse(readFileSync(path.join(__dirname, '..', 'package.json')));
+      this.value = pkg.version;
+    }
+    return this.value;
+  }
+};
 
 program.version(version);