Use os.sync() instead of sync command (#4278)

archinstall/lib/installer.py

@@ -144,7 +144,8 @@ class Installer:
 			# Return None to propagate the exception
 			return None
 
-		self.sync()
+		info(tr('Syncing the system...'))
+		os.sync()
 
 		if not (missing_steps := self.post_install_check()):
 			msg = f'Installation completed without any errors.\nLog files temporarily available at {logger.directory}.\nYou may reboot when ready.\n'
@@ -163,10 +164,6 @@ class Installer:
 			self.sync_log_to_install_medium()
 			return False
 
-	def sync(self) -> None:
-		info(tr('Syncing the system...'))
-		SysCommand('sync')
-
 	def remove_mod(self, mod: str) -> None:
 		if mod in self._modules:
 			self._modules.remove(mod)