Replace python subprocess's universal_newlines with text. NFC

In python 3.7 the `universal_newlines` parameter was deprecated in
favor of the more readable `text` parameter.

We updated our minimum supported python version to 3.8 in #23417.

Author: sbc100

test/jsrun.py

@@ -106,7 +106,7 @@ def run_js(filename, engine, args=None,
         stderr=stderr,
         cwd=cwd,
         timeout=timeout,
-        universal_newlines=True)
+        text=True)
   except Exception:
     # the failure may be because the engine is not present. show the proper
     # error in that case

tools/maint/check_for_closed_issues.py

@@ -16,7 +16,7 @@
 
 
 def run(*args, **kwargs):
-  kwargs['universal_newlines'] = True
+  kwargs['text'] = True
   return subprocess.check_output(*args, **kwargs)
 
 

tools/shared.py

@@ -126,7 +126,7 @@ def run_process(cmd, check=True, input=None, *args, **kw):
   # output before messages that we have already written.
   sys.stdout.flush()
   sys.stderr.flush()
-  kw.setdefault('universal_newlines', True)
+  kw.setdefault('text', True)
   kw.setdefault('encoding', 'utf-8')
   ret = subprocess.run(cmd, check=check, input=input, *args, **kw)
   debug_text = '%sexecuted %s' % ('successfully ' if check else '', shlex_join(cmd))