launch.py: Don't involve shell for running Python or Git for output

Fixes Linux regression in 451d255b58

launch.py

@@ -58,7 +58,7 @@ Use --skip-python-version-check to suppress this warning.
 @lru_cache()
 def commit_hash():
     try:
-        return subprocess.check_output(f"{git} rev-parse HEAD", encoding='utf8').strip()
+        return subprocess.check_output([git, "rev-parse", "HEAD"], shell=False, encoding='utf8').strip()
     except Exception:
         return "<none>"
 
@@ -66,7 +66,7 @@ def commit_hash():
 @lru_cache()
 def git_tag():
     try:
-        return subprocess.check_output(f"{git} describe --tags", encoding='utf8').strip()
+        return subprocess.check_output([git, "describe", "--tags"], shell=False, encoding='utf8').strip()
     except Exception:
         return "<none>"
 
@@ -125,7 +125,7 @@ def run_pip(command, desc=None, live=default_command_live):
 
 
 def check_run_python(code: str) -> bool:
-    result = subprocess.run([python, "-c", code], capture_output=True, shell=True)
+    result = subprocess.run([python, "-c", code], capture_output=True, shell=False)
     return result.returncode == 0