Use a comma as the fr_FR decimal separator

[ckarnell]

fr_FR is the only entry in _DECIMAL_SEPARATOR with a dot. Every other locale there pairs a group separator with a comma, including hu_HU and lv, which group with a space exactly like French does.

humanize.i18n.activate("fr_FR")
humanize.intcomma(1_234_567.89)   # "1 234 567.89", want "1 234 567,89"
humanize.intword(1_000)           # "1.0 mille",    want "1,0 mille"

You already worked this out in #357: the dot came from #248, and merwok said French needs the comma. That PR was closed by its author before it landed. So the value is still there.

One line of data. Plus the 26 fr_FR expectations that encoded the old output.

naturalsize is deliberately untouched, and it is the one loose end. filesize.py never reads the separator, so it still prints 42.0 Ko while intcomma now prints a comma. #357 tried to fix both together and picked up a 10% performance report on the bundle, so this leaves that half alone. Happy to send it separately if you want it, and it's a fair reason to hold this one.

Tests are 789 passing before and after, same set. Reverting just the i18n.py line fails exactly the 26 updated expectations and nothing else, so the tests are pinned to the change, not to the diff.

[Mukller]

Verified locally on the PR branch (Python 3.13): pytest tests/test_i18n.py — 6 passed, including the updated fr_FR assertions for both intcomma (1 234 567,89) and the full naturaldelta matrix (1,0 mille … 1,0 milliard).

The substance is unambiguous: French uses the comma as its decimal separator (per standard French typography and every other locale entry in that same mapping), so "." in _DECIMAL_SEPARATOR["fr_FR"] was simply wrong. This PR aligns fr_FR with de_DE/it_IT/pt_BR/hu_HU rather than introducing anything novel.

One note for the changelog: this changes every fr_FR-formatted decimal output at once — downstream consumers who (incorrectly) parsed humanize's French output against the old dot will see different strings. Worth an explicit line as a behavior fix.

Approving.

[hugovk]

Merci!

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 99.56%. Comparing base (2ad3641) to head (9b579cd).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #378   +/-   ##
=======================================
  Coverage   99.56%   99.56%           
=======================================
  Files          12       12           
  Lines         927      927           
=======================================
  Hits          923      923           
  Misses          4        4           

Flag	Coverage Δ
macos-latest	97.62% <100.00%> (ø)
ubuntu-latest	97.62% <100.00%> (ø)
windows-latest	95.46% <0.00%> (ø)

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.