Add snowflake 2.9.1.

versions.json

@@ -128,6 +128,22 @@
     }
   },
   "snowflake": {
+    "2.9.1": {
+      "repo_url": "https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake.git",
+      "revision": "b130151b24db155e4ea89517b72b73b21949c84b",
+      "build_path": "client",
+      "repo_dir": "snowflake",
+      "go": {
+        "version": "go1.19.3",
+        "sha256": "18ac263e39210bcf68d85f4370e97fb1734166995a1f63fb38b4f6e07d90d212"
+      },
+      "ndk": {
+        "url": "https://dl.google.com/android/repository/android-ndk-r23c-linux.zip",
+        "revision": "23.2.8568313",
+        "sha256": "6ce94604b77d28113ecd588d425363624a5228d9662450c48d2e4053f8039242"
+      },
+      "timestamp": "201001010000.00"
+    },
     "2.5.1": {
       "repo_url": "https://gitlab.torproject.org/tpo/anti-censorship/pluggable-transports/snowflake.git",
       "revision": "7b77001eaa90e09d41172a2b170dabd3f1922b4a",