morshu-server: fix startup by passing env and using sys.executable

ttstoy/ttstoy.py

@@ -1,4 +1,5 @@
 import os
+import sys
 import shutil
 import logging
 import asyncio
@@ -527,10 +528,14 @@ class TtsToy(Cog):
                 log.error(f"Morshu server not found: {server_py}")
                 return False
 
+            env = os.environ.copy()
+            env['PORT'] = str(self.morshu_port)
+
             self.morshu_process = await asyncio.to_thread(
                 subprocess.Popen,
-                ["python3", "server.py"],
+                [sys.executable, "server.py"],
                 cwd=str(self.morshu_dir),
+                env=env,
                 stdout=subprocess.PIPE,
                 stderr=subprocess.PIPE,
                 text=True