fix(cron): validate comma-separated lists of ranges and steps

[patchwright]

Summary

cron() rejects valid expressions whose components are comma-separated lists of ranges or steps, e.g. cron("1-5,10-20 * * * *") raises ValidationError even though the expression is valid.

Reproduction

from validators import cron

cron("1-5,10-20 * * * *")   # ValidationError (incorrect)
cron("1-5,30 * * * *")      # ValidationError (incorrect)

Validity currently depends on element order, which is the clearest sign this is a bug rather than an intended limitation:

cron("30,1-5 * * * *")      # True
cron("1-5,30 * * * *")      # ValidationError  (same tokens, different order)

Cause

In src/validators/cron.py, _validate_cron_component checks the "-" and "/" branches before the "," branch. A component like "1-5,10-20" therefore matches the range branch, split("-") yields three parts, and the whole expression is rejected.

Fix

Evaluate the "," branch first, recursing on each element so each element can itself be a single value, a range ("1-5"), or a step ("*/2").

     if component == "*":
         return True

+    if "," in component:
+        for item in component.split(","):
+            if not _validate_cron_component(item, min_val, max_val):
+                return False
+        return True
+
     if component.isdecimal():

No previously-accepted input changes behaviour: any component containing a comma previously hit the range branch and was rejected, so this only accepts inputs that were wrongly rejected. The existing dead commented all(...) block is removed.

Tests

Adds four cases to test_returns_true_on_valid_cron:

• "1-5,10-20 * * * *"
• "1-5,30 * * * *"
• "10,20-30 * * * *"
• "1-5,10-20,30-40 * * * *"

Each fails on the current code and passes with the fix. Full suite: 895 → 899 passing. ruff check / ruff format clean.

I couldn't find an existing issue or PR covering this — happy to fold it into one if I missed it.