WooCommerce Subscriptions 6.9.0

* Fix: Prevent fatal errors when the retry migration doesn't receive a valid retry object. PR#3042
* Fix: Fix PHP notices in subscription events by date report. PR#3078
* Fix: Don't trigger payment gateways while processing retries on staging sites. PR#2870
* Fix: Apply coupons and discounts to initial payment and early renewal carts. PR#3048
* Fix: Use the correct `for` attribute in the variable_subscription_trial_period label element. PR#3081
* Fix: [PayPal Standard] Prevent creating multiple orders to record a single sign up transaction that was previously handled by a PDT request. PR#3074
* Tweak: Remove the nonce from early renewal urls. PR#3085

* Fix: Pass the quantity argument to woocommerce_add_cart_item_data filter. PR#3051
* Dev: Update Action Scheduler to 2.1.1. PR#3059

* Fix: Always get the subscription's customer user from post meta. Fixes issues on sites running WC 3.5 where the subscription customer was incorrectly being set to an admin user. PR#3037
* Fix: Use the current timestamp of site's timezone for comparison during synchronisation first payment date calculations. PR#3003
* Fix: Sort the user subscriptions cache to ensure subscriptions appear in the correct order on the My Account > Subscriptions page. PR#2965
* Fix: Correctly account for tax inclusive sign up fees for synced products. PR#2818
* Fix: Fix PHP 7.1.x warnings related to get_sign_up_fee() and product variations. PR#3014
* Fix: Use the correct breadcrumbs on "change payment method" and "change address" pages. PR#3008
* Fix: Fix product purchasability issues when switching between limited variable products. PR#3007
* Fix: Remove the erasure tools link from the description of the erasure setttings for users without the manage_privacy_options capability. PR#3004
* Dev: Add switch proration filters. PR#3011
* Dev: Use admin_created_subscription hook to generate download permissions. PR#3024
* Dev: Deprecated wcs_get_sites_timezone() fixes get_local_timezone() deprecated warnings. PR#3032