argparse_manpage: cleanup, add tests, fix CLI

dev-python/argparse-manpage/patches/argparse_manpage-4.6.patchset

@@ -0,0 +1,32 @@
+From c2bf43d175936336e6528d2c4ca36fd3c2bfe3c8 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Joachim=20Mairb=C3=B6ck?= <j.mairboeck@gmail.com>
+Date: Sun, 25 Aug 2024 12:21:53 +0200
+Subject: Use sys.stdout instead of /dev/stdout
+
+`/dev/stdout` isn't portable, it isn't available everywhere, e.g. on Haiku.
+
+diff --git a/argparse_manpage/tooling.py b/argparse_manpage/tooling.py
+index ef5c59c..1452518 100644
+--- a/argparse_manpage/tooling.py
++++ b/argparse_manpage/tooling.py
+@@ -71,9 +71,11 @@ def write_to_filename(text, filename):
+     Write given text into a filename at once.  Pre-create the parent directory
+     if it doesn't exist yet.  Print to stdout if filename == '-'.
+     """
+-    filename = filename if filename != '-' else '/dev/stdout'
+-    dirname = os.path.dirname(filename)
+-    if dirname and not os.path.exists(dirname):
+-        os.makedirs(dirname)
+-    with open(filename, 'w') as stream:
+-        stream.write(text)
++    if filename == '-':
++        sys.stdout.write(text)
++    else:
++        dirname = os.path.dirname(filename)
++        if dirname and not os.path.exists(dirname):
++            os.makedirs(dirname)
++        with open(filename, 'w') as stream:
++            stream.write(text)
+-- 
+2.45.2
+