[Bug] api_*_version override has no effect on PAL-based service URLs

Context

AdyenClient._set_url_version uses the following regex to replace the API version in endpoint URLs:

endpoint = re.sub(r"\.com/v\d{1,2}", f".com/{new_version}", endpoint)

This only matches URLs where the version segment appears immediately after the domain, e.g.:

• checkout-test.adyen.com/v71 ✓
• management-test.adyen.com/v3 ✓

It does not match PAL-based URLs where the version is deeper in the path, e.g.:

• pal-test.adyen.com/pal/servlet/Recurring/v68 ✗
• pal-test.adyen.com/pal/servlet/Payment/v68 ✗
• pal-test.adyen.com/pal/servlet/BinLookup/v54 ✗

Proposed Change

Update the regex to match a version segment anywhere in the path:

endpoint = re.sub(r"/v\d+(?=/|$)", f"/{new_version}", endpoint)

Also add a None guard to avoid corrupting unrelated service URLs when only one api_*_version is set:

version = version_lookup[service]
if version is None:
    return endpoint

Benefit

Setting api_recurring_version, api_payment_version, api_payout_version, api_bin_lookup_version, or api_stored_value_version on AdyenClient currently has no effect. The fix makes version overrides work consistently across all services.

Start at AdyenClient.set_url_version and inspect how the version lookup is applied to service endpoint URLs. Check the listed PAL-based endpoints and existing URL-version behavior, then verify that each api*_version override changes its matching path while an unset version leaves unrelated URLs unchanged.