Publish a new release to support building `socksio` from source on Python 3.14

[SigureMo]

Installing the wheel for socksio on Python 3.14 works fine, but installing from source fails due to a bug in flit_core v2. Reproduction steps:

$ python -m venv socksio-env
$ source socksio-env/bin/activate
$ pip install --no-binary socksio socksio
Collecting socksio
  Downloading socksio-1.0.0.tar.gz (19 kB)
  Installing build dependencies ... done
  Getting requirements to build wheel ... done
  Preparing metadata (pyproject.toml) ... error
  error: subprocess-exited-with-error
  
  × Preparing metadata (pyproject.toml) did not run successfully.
  │ exit code: 1
  ╰─> [21 lines of output]
      Traceback (most recent call last):
        File "/Users/nyakku/Projects/yutto/socksio-env/lib/python3.14/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 389, in <module>
          main()
          ~~~~^^
        File "/Users/nyakku/Projects/yutto/socksio-env/lib/python3.14/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 373, in main
          json_out["return_val"] = hook(**hook_input["kwargs"])
                                   ~~~~^^^^^^^^^^^^^^^^^^^^^^^^
        File "/Users/nyakku/Projects/yutto/socksio-env/lib/python3.14/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 175, in prepare_metadata_for_build_wheel
          return hook(metadata_directory, config_settings)
        File "/private/var/folders/6g/d8nyqgsx009gszprx9qf0nl80000gn/T/pip-build-env-mw7dy2oe/overlay/lib/python3.14/site-packages/flit_core/buildapi.py", line 29, in prepare_metadata_for_build_wheel
          metadata = make_metadata(module, ini_info)
        File "/private/var/folders/6g/d8nyqgsx009gszprx9qf0nl80000gn/T/pip-build-env-mw7dy2oe/overlay/lib/python3.14/site-packages/flit_core/common.py", line 368, in make_metadata
          md_dict.update(get_info_from_module(module))
                         ~~~~~~~~~~~~~~~~~~~~^^^^^^^^
        File "/private/var/folders/6g/d8nyqgsx009gszprx9qf0nl80000gn/T/pip-build-env-mw7dy2oe/overlay/lib/python3.14/site-packages/flit_core/common.py", line 178, in get_info_from_module
          docstring, version = get_docstring_and_version_via_ast(target)
                               ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^
        File "/private/var/folders/6g/d8nyqgsx009gszprx9qf0nl80000gn/T/pip-build-env-mw7dy2oe/overlay/lib/python3.14/site-packages/flit_core/common.py", line 134, in get_docstring_and_version_via_ast
          isinstance(child.value, ast.Str))
                                  ^^^^^^^
      AttributeError: module 'ast' has no attribute 'Str'
      [end of output]
  
  note: This error originates from a subprocess, and is likely not a problem with pip.
error: metadata-generation-failed

× Encountered error while generating package metadata.
╰─> See above for output.

note: This is an issue with the package mentioned above, not pip.
hint: See above for details.

This may cause Homebrew formulas that depend on socksio to fail to build/install on Python 3.14, because they build from source.

Because ast.Str has been removed in Python 3.14^1, and when building socksio==1.0.0 (the latest release on PyPI) from source it depends on flit_core >=2,<3. flit_core v2 has a bug on Python 3.14 that prevents building from source. This issue is fixed in flit_core v3.10.0 (see pypa/flit#684). Therefore, removing the <3 upper bound on flit_core — i.e., requiring flit_core >=3 — will resolve the problem (due to this issue, it is recommended to update the flit_core version requirement to >=3).

I noticed #61 already removed the <3 constraint, so publishing a new release should resolve this issue.