fix: quote filenames when making registries

[binggao1230]

Fixes #369.

Pooch.load_registry already uses shlex.split, so filenames with spaces can be read when they are quoted. make_registry was still writing raw filenames, which made generated registries ambiguous for names like LICENSE (copy).

This updates make_registry to quote the normalized registry filename with shlex.quote and adds a round-trip test for a filename containing spaces.

Verification:

uv run --with pytest --with-editable . pytest pooch/tests/test_hashes.py -q
uv run --with pytest --with pytest-httpserver --with pytest-localftpserver --with-editable . pytest pooch/tests/test_hashes.py pooch/tests/test_core.py -q
uv run --with ruff ruff check pooch/hashes.py pooch/tests/test_hashes.py
uv run --with ruff ruff format --check pooch/hashes.py pooch/tests/test_hashes.py
git diff --check

[binggao1230]

The failing test jobs look unrelated to this change. In each failed job, the new regression test passes:

../tests/test_hashes.py::test_make_registry_quotes_files_with_spaces PASSED

The failures are all from the existing pooch.downloaders.HTTPDownloader doctest calling https://httpbin.org/basic-auth/doggo/goodboy, which returned 503/504 or timed out. The network-enabled job passed, and local full tests passed for me:

uv run --with pytest --with pytest-httpserver --with pytest-localftpserver --with-editable . pytest -q
# 142 passed, 19 skipped

I tried to rerun failed jobs, but GitHub does not allow me to rerun checks on the upstream repo.