gh-58032: Do not use argparse.FileType in module CLIs and scripts (GH-113649)

Open and close files manually. It prevents from leaking files,
preliminary creation of output files, and accidental closing of stdin
and stdout.

Lib/json/tool.py

@@ -13,7 +13,6 @@ Usage::
 import argparse
 import json
 import sys
-from pathlib import Path
 
 
 def main():
@@ -22,11 +21,9 @@ def main():
                    'to validate and pretty-print JSON objects.')
     parser = argparse.ArgumentParser(prog=prog, description=description)
     parser.add_argument('infile', nargs='?',
-                        type=argparse.FileType(encoding="utf-8"),
                         help='a JSON file to be validated or pretty-printed',
-                        default=sys.stdin)
+                        default='-')
     parser.add_argument('outfile', nargs='?',
-                        type=Path,
                         help='write the output of infile to outfile',
                         default=None)
     parser.add_argument('--sort-keys', action='store_true', default=False,
@@ -59,23 +56,30 @@ def main():
         dump_args['indent'] = None
         dump_args['separators'] = ',', ':'
 
-    with options.infile as infile:
+    try:
+        if options.infile == '-':
+            infile = sys.stdin
+        else:
+            infile = open(options.infile, encoding='utf-8')
         try:
             if options.json_lines:
                 objs = (json.loads(line) for line in infile)
             else:
                 objs = (json.load(infile),)
+        finally:
+            if infile is not sys.stdin:
+                infile.close()
 
-            if options.outfile is None:
-                out = sys.stdout
-            else:
-                out = options.outfile.open('w', encoding='utf-8')
-            with out as outfile:
-                for obj in objs:
-                    json.dump(obj, outfile, **dump_args)
-                    outfile.write('\n')
-        except ValueError as e:
-            raise SystemExit(e)
+        if options.outfile is None:
+            outfile = sys.stdout
+        else:
+            outfile = open(options.outfile, 'w', encoding='utf-8')
+        with outfile:
+            for obj in objs:
+                json.dump(obj, outfile, **dump_args)
+                outfile.write('\n')
+    except ValueError as e:
+        raise SystemExit(e)
 
 
 if __name__ == '__main__':