Fix compatibility with pyrate-limiter 4.0.1

[Copilot]

pyrate-limiter 4.0.1 removed BucketFullException from its public API, breaking module imports.

Changes

Dependency constraint

• Allow pyrate-limiter v4.x (>=3.7.0,<5)

Rate limiting pattern migration

• Replace exception-based pattern with return value checks using blocking=False
• Remove BucketFullException import and try/except blocks
• Remove deprecated max_delay parameter from Limiter initialization

Example migration

# v3.x
try:
    await self._login_limiter.try_acquire_async("login")
except BucketFullException as ex:
    raise RoborockRateLimit("Rate limit reached") from ex

# v4.x
success = await self._login_limiter.try_acquire_async("login", blocking=False)
if not success:
    raise RoborockRateLimit("Rate limit reached")

Test fixtures

• Mock try_acquire_async to return True (in addition to existing try_acquire)

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Compatibility issue with latest pyrate-limiter release 4.0.1</issue_title>
<issue_description>### Description

With the latest release of pyrate-limiter, 4.0.1, python-roborock raises an ImportError during module import due to a change in pyrate-limiter public exports.

The exception BucketFullException is no longer exposed at the top-level pyrate_limiter package,
https://github.com/vutran1710/PyrateLimiter/blob/master/docs/migrating.md

which breaks the import in roborock/web_api.py.

---

Error

ImportError: cannot import name 'BucketFullException' from 'pyrate_limiter'
</issue_description>

## Comments on the Issue (you are @copilot in this section)

<comments>
</comments>

• Fixes Compatibility issue with latest pyrate-limiter release 4.0.1 #751

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[codecov]

Codecov Report

❌ Patch coverage is 26.92308% with 19 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
roborock/web_api.py	26.92%	14 Missing and 5 partials ⚠️

Files with missing lines	Coverage Δ
tests/fixtures/web_api_fixtures.py	100.00% <ø> (ø)
roborock/web_api.py	52.31% <26.92%> (-0.43%)	⬇️

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