Fix the build/tests against Python 3.13

Release v4.6

Fix the build against Python 3.13

argparse-manpage v4.5

• We newly provide build_manpages.build_py and build_manpages.install
  command classes that are re-usable from pyproject.toml. No need to
  provide setup.py because of argparse-manpage. Solved issue#85.

argparse-manpage v4.4

WARNING: The 'build_manpage' setup.py command will be removed v5
WARNING: We'll drop the Python 2.7 support in v5

News in v4.4

• The prog= specifier (in setup.py/setup.cfg/pyproject.toml) is now
  better handled so it doesn't conflict with ArgumentParser(prog=..).
  Fixes #79

argparse-manpage v4.3

WARNING: The 'build_manpage' setup.py command will be removed v5
WARNING: We'll drop the Python 2.7 support in v5

News in v4.3

• The pyproject.toml parsing feature now depends on the python3-tomli library
  instead of python-toml for "python_environment >3, <=3.10".

argparse-manpage v4.2

WARNING: The 'build_manpage' setup.py command will be removed v5
WARNING: We'll drop the Python 2.7 support in v5

News in v4.2

• Support for pyproject.toml specification of manpages added.

• Support for pre-written man pages (the --manfile option)

Bugfixes in version 4.2

• Incorrect dict access for --include support fixed.

• Provide useful AUTHORS section with e-mail from
  Distribution.get_author_email() even if Distribution.get_author() returns
  None.

argparse-manpage v4.1

WARNING: The 'build_manpage' setup.py command will be removed v5
WARNING: We'll drop the Python 2.7 support in v5=

News in v4.1

• A new --include feature, inspired by help2man --include.

• Allow overriding build date with SOURCE_DATE_EPOCH environment variable
  in order to make builds reproducible. See this link for more info:
  https://reproducible-builds.org/specs/source-date-epoch/

• The AUTHORS section was changed to more standard AUTHOR.

Release v4

WARNING: The 'build_manpage' setup.py command will be removed v5
WARNING: We'll drop the Python 2.7 support in v5

News in v4

• The manual page generator logic is now separated from the 'build_manpages'
  module (which provides setup.py integration helpers). Therefore the
  argparse-manpage doesn't necessarily have to depend on setuptools.
  Projects that want to integrate using 'setup.py' should though place a new
  "extra" named 'argparse-manpage[setuptools]' into their set of build
  requirements in project.toml file.

• The old 'build_manpage' command (!= 'build_manpages') is now more
  isolated from the rest of the code, likely never loaded.

• the Manpage class API was changed in v3 so it required an additional
  constructor 'data' argument. This change was reverted, and the only
  argument is again the ArgumentParser object.

• The 'version' and 'description' options were fixed.

• New options 'manual_section' and 'manual_title' were added.

• The manual page now automatically generates a current date in headers.

• Several groff escaping issues were fixed.

argparse-manpage v3

• New man page format: single-commands-section
• Add CLI and conf options for setting the output format
• Add CLI and conf options to explicitly specify %prog value
• Skip showing commands with help == SUPPRESS
• Avoid rendering docs for command aliases
• Print program name in upper case in header and footer
• The --author CLI option has changed, and takes arbitrary string
  (typically 'Author Name the@example.com'), and newly can be specified
  multiple times. Therefore, it now replaces the '--author-email' option.
  The --author-email option is kept, but is just an alias to the --author
  option.
• All CLI options can be specified also in setup.cfg
• Don't render AUTHORS and DISTRIBUTION if they would contain undefined values
• Remove '... was written by' from AUTHORS

argparse-manpage v2.2

• Fixed the testsuite against the setuptools v60+

Version 2.1

New in version 2.1

• Output manual pages should be built reproducibly, no matter the current
  size of the terminal.

• Methods build_manpages, get_build_py_cmd, get_install_cmd are now
  provided in top-level module.

• More portable opening and parsing given by python file name.