Fix system check output encoding

Fixes #1684

This commit explicitly specifies "utf-8" encoding when calling latex tools
in `latextools_system_check` command. That's the encoding, which is used when
calling latex commands in `make_pdf` etc. as well.

Author: deathaxe

latextools/system_check.py

@@ -494,11 +494,12 @@ def check_output(self, cmd: list[str]) -> str | None:
         result = subprocess.run(
             cmd,
             env=self.env,
+            encoding="utf-8",
             shell=self.platform == "windows",
             stderr=subprocess.DEVNULL,
             stdout=subprocess.PIPE,
-            text=True,
             timeout=30,
+            universal_newlines=True,
         )
         return result.stdout if result.returncode == 0 else None