fix(deps): drop unused undici dependency (#153)

undici was declared as a direct dependency but is never required
anywhere in this package - grep across index.js, lib/ and stubs/ finds
no reference to undici, ProxyAgent, setGlobalDispatcher or Dispatcher.
The one HTTP call in lib/synth-audio.js uses the global fetch, and
Azure proxy support goes through the SDK's own setProxy plus the
http_proxy_ip/http_proxy_port params.

Removing it clears all seven open undici advisories from npm audit for
this package and its consumers, and stops speech-utils pulling a
duplicate undici 7.x into trees where the consumer already depends on
undici 8 (feature-server does).

Lint passes; full test suite passes 105/105 with live vendor credentials.

Co-authored-by: Claude Opus 5 <noreply@anthropic.com>

package-lock.json

@@ -20,8 +20,7 @@
         "debug": "^4.3.4",
         "google-protobuf": "^3.21.2",
         "microsoft-cognitiveservices-speech-sdk": "^1.51.0",
-        "openai": "^4.98.0",
-        "undici": "^7.5.0"
+        "openai": "^4.98.0"
       },
       "devDependencies": {
         "config": "^4.2.0",
@@ -7066,15 +7065,6 @@
         "url": "https://github.com/sponsors/ljharb"
       }
     },
-    "node_modules/undici": {
-      "version": "7.24.5",
-      "resolved": "https://registry.npmjs.org/undici/-/undici-7.24.5.tgz",
-      "integrity": "sha512-3IWdCpjgxp15CbJnsi/Y9TCDE7HWVN19j1hmzVhoAkY/+CJx449tVxT5wZc1Gwg8J+P0LWvzlBzxYRnHJ+1i7Q==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=20.18.1"
-      }
-    },
     "node_modules/undici-types": {
       "version": "5.26.5",
       "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-5.26.5.tgz",
@@ -12415,11 +12405,6 @@
         "which-boxed-primitive": "^1.0.2"
       }
     },
-    "undici": {
-      "version": "7.24.5",
-      "resolved": "https://registry.npmjs.org/undici/-/undici-7.24.5.tgz",
-      "integrity": "sha512-3IWdCpjgxp15CbJnsi/Y9TCDE7HWVN19j1hmzVhoAkY/+CJx449tVxT5wZc1Gwg8J+P0LWvzlBzxYRnHJ+1i7Q=="
-    },
     "undici-types": {
       "version": "5.26.5",
       "resolved": "https://registry.npmjs.org/undici-types/-/undici-types-5.26.5.tgz",

package.json

@@ -36,8 +36,7 @@
     "debug": "^4.3.4",
     "google-protobuf": "^3.21.2",
     "microsoft-cognitiveservices-speech-sdk": "^1.51.0",
-    "openai": "^4.98.0",
-    "undici": "^7.5.0"
+    "openai": "^4.98.0"
   },
   "devDependencies": {
     "config": "^4.2.0",