Product meta lookup table incorrectly shows product on sale

[pintend]

Prerequisites

• I have carried out troubleshooting steps and I believe I have found a bug.
• I have searched for similar bugs in both open and closed issues and cannot find a duplicate.

Describe the bug

If i product has its _sale_price and _regular_price the same then _price will also be the same. $product->is_on_sale() will correctly return false as it checks against the regular price but the lookup table will show on sale as it ignores the regular price and just checks if the _price is the same as the _sale_price

It may be incorrect to have all 3 prices be the same, but it can happen and it will cause this behavior. In my case its not in my control as we are working with a company which integrates our products/inventory with another system (which is where prices are configured) I have an issue opened with them as well to not populate the _sale_price meta field when its the same. but regardless i think this should also be fixed here

Expected behavior

wp_wc_product_meta_lookup.onsale should be 0 when $product->is_on_sale() is false

Actual behavior

wp_wc_product_meta_lookup.onsale can sometimes be 1 when $product->is_on_sale() is false

Steps to reproduce

set regular_price, price, and sale_price to the same value and generate lookup tables`

WordPress Environment

N/A

Isolating the problem

• I have deactivated other plugins and confirmed this bug occurs when only WooCommerce plugin is active.
• This bug happens with a default WordPress theme active, or Storefront.
• I can reproduce this bug consistently using the steps above.