high_value_council_tax_surcharge not filtered under abolish_council_tax

[MaxGhenis]

high_value_council_tax_surcharge is included in household_tax.adds (line 18) and gov_tax.adds (line 18), but neither household_tax.formula nor gov_tax.formula filters it out when gov.contrib.abolish_council_tax is True. They only filter council_tax:

# household_tax.formula:
if abolish_council_tax:
    return add(
        household,
        period,
        [tax for tax in household_tax.adds if tax not in ["council_tax"]],
    )

If abolishing council tax is the intent, the high-value surcharge presumably goes with it — the surcharge is defined on top of council tax bands. Suggest extending the filter to:

[tax for tax in household_tax.adds if tax not in ["council_tax", "high_value_council_tax_surcharge"]]

in both household_tax.formula and gov_tax.formula. Probably also needs corresponding behaviour in pre_budget_change_household_tax.formula (which currently doesn't include the surcharge — separate question whether it should).

Found while reviewing #1668.