WooCommerce Analytics: Add backwards compatibility for add_request_timestamp_and_nocache() (#45988)

* Add backwards compatibility for WC_Tracks_Client::add_request_timestamp_and_nocache()

The add_request_timestamp_and_nocache() method was introduced in WooCommerce 9.7.0. This commit adds a compatibility check to prevent fatal errors when running with older WooCommerce versions.

When the method is not available, the code now falls back to manually appending the timestamp and nocache parameters to the pixel URL, replicating the exact behavior of the newer method.

This ensures WooCommerce Analytics tracking continues to work correctly across all supported WooCommerce versions.

* changelog

Committed via a GitHub action: https://github.com/Automattic/jetpack/actions/runs/19486768708

Upstream-Ref: Automattic/jetpack@e04e854

Author: grzegorz-cp