Nova Scotia Age amount supplement

Add new files
Fixes PolicyEngine#455

changelog_entry.yaml

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+

policyengine_canada/parameters/gov/provinces/ns/tax/income/credits/age/age_supplement/base.yaml

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+description: Nova Scotia adds this additional amount to the basic personal amount.
+values: 
+  2022-01-01: 1_465
+metadata:
+  unit: currency-CAD
+  label: Nova Scotia basic personal amount additional base
+  reference: 
+  - title: 2022 Nova Scotia Personal Tax Credits Return
+    href: https://hr.acadiau.ca/files/sites/hr/Payroll/Pensions%20&%20Benefits/NS_TD1_2022.pdf#page=1
+  - title: 2022 Worksheet NS428
+    href: https://www.canada.ca/content/dam/cra-arc/formspubs/pbg/5003-d/5003-d-22e.pdf#page=1
+  - title: Nova Scotia income tax act - subdivision c - Deduction for employment out of Canada
+    href: https://nslegislature.ca/sites/default/files/legc/statutes/income%20tax.pdf#page=24

policyengine_canada/parameters/gov/provinces/ns/tax/income/credits/age/age_supplement/phase_out_rate.yaml

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+description: Nova Scotia phases its age amount supplement out at this rate.
+brackets:
+  - threshold:
+      2022-01-01: 0
+    rate:
+      2022-01-01: 0
+  - threshold:
+      2022-01-01: 25_000
+    rate:
+      2022-01-01: 0.0293
+
+metadata:
+  type: marginal_rate
+  rate_unit: /1
+  threshold_unit: currency-CAD
+  period: year 
+  label: Nova Scotia basic personal amount phase out rate
+  reference: 
+  - title: 2022 Nova Scotia Personal Tax Credits Return
+    href: https://hr.acadiau.ca/files/sites/hr/Payroll/Pensions%20&%20Benefits/NS_TD1_2022.pdf#page=1
+  - title: 2022 Worksheet NS428
+    href: https://www.canada.ca/content/dam/cra-arc/formspubs/pbg/5003-d/5003-d-22e.pdf#page=1
+  - title: Nova Scotia income tax act - subdivision c - Deduction for employment out of Canada
+    href: https://nslegislature.ca/sites/default/files/legc/statutes/income%20tax.pdf#page=24

policyengine_canada/tests/gov/provinces/ns/tax/income/credits/age/ns_age_amount_supplement.yaml

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+- name: Nova Scotia Age amonut supplement; eligible age with eligible taxable income below 25_000
+  period: 2023
+  input:
+    province_code: NS
+    age: 65
+    ns_taxable_income: 24_999
+  output:
+    ns_age_tax_credit: 1_465
+
+- name: Nova Scotia Age amonut supplement; eligible age with eligible taxable income between 25_000 and 75_000
+  period: 2023
+  input:
+    province_code: NS
+    age: 65
+    ns_taxable_income: 65_000
+  output:
+    ns_age_tax_credit: 295
+
+- name: Nova Scotia Age tax credit; eligible age with ineligible taxable income more than 75_000
+  period: 2023
+  input:
+    province_code: NS
+    age: 65
+    ns_taxable_income: 75_001
+  output:
+    ns_age_tax_credit: 0
+
+- name: Nova Scotia Age tax credit; ineligible age with eligible taxable income
+  period: 2023
+  input:
+    province_code: NS
+    age: 64
+    ns_taxable_income: 24_999
+  output:
+    ns_age_tax_credit: 0
+
+- name: Nova Scotia Age tax credit; ineligible age with ineligible taxable income
+  period: 2023
+  input:
+    province_code: NS
+    age: 64
+    ns_taxable_income: 75_001
+  output:
+    ns_age_tax_credit: 0

policyengine_canada/variables/gov/provinces/ns/tax/income/credits/age/ns_age_amount_supplement.py

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+from policyengine_canada.model_api import *
+
+
+class ns_age_amount_supplement(Variable):
+    value_type = float
+    entity = Person
+    label = "Nova Scotia Basic Personal Amount"
+    unit = CAD
+    definition_period = YEAR
+    defined_for = ProvinceCode.NS
+    reference = (
+        "https://hr.acadiau.ca/files/sites/hr/Payroll/Pensions%20&%20Benefits/NS_TD1_2022.pdf#page=1",
+        "https://www.canada.ca/content/dam/cra-arc/formspubs/pbg/5003-d/5003-d-22e.pdf#page=1",
+        "https://nslegislature.ca/sites/default/files/legc/statutes/income%20tax.pdf#page=24",
+    )
+
+    def formula(person, period, parameters):
+        p = parameters(period).gov.provinces.ns.tax.income.credits.age
+        age = person("age", period)
+        taxable_income = person("ns_taxable_income", period)
+
+        # is eligible for age amount supplement
+        eligibility = age >= p.age_eligibility
+
+        # Calculate additional amount added to base amount
+        reduced_additional_amount = max_(
+            0,
+            p.age_supplement.base
+            - p.age_supplement.phase_out_rate.calc(taxable_income),
+        )
+
+        return reduced_additional_amount