Fix path seperator in var (#719)

* Fix path seperator in var

":" on Unix vs ";" on Windows

* Fix os pathsep on an other case

Again pathsep is ":" on Unix & ";" on Windows

lib/esbonio/esbonio/server/features/sphinx_manager/client_subprocess.py

@@ -346,7 +346,7 @@ def _on_progress(params):
 
 def get_sphinx_env(config: SphinxConfig) -> Dict[str, str]:
     """Return the set of environment variables to use with the Sphinx process."""
-    env = {"PYTHONPATH": ":".join([str(p) for p in config.python_path])}
+    env = {"PYTHONPATH": os.pathsep.join([str(p) for p in config.python_path])}
 
     passthrough = set(config.env_passthrough)
     if IS_WIN and "SYSTEMROOT" not in passthrough:
@@ -356,7 +356,7 @@ def get_sphinx_env(config: SphinxConfig) -> Dict[str, str]:
         value = os.environ.get(envname, None)
         if value is not None:
             if envname == "PYTHONPATH":
-                env["PYTHONPATH"] = f"{env['PYTHONPATH']}:{value}"
+                env["PYTHONPATH"] = f"{env['PYTHONPATH']}{os.pathsep}{value}"
             else:
                 env[envname] = value