Montana 10% EITC match applicable year (#5359)

* Montana 10% EITC match applicable year
Fixes #5358

* format

* minor

changelog_entry.yaml

@@ -0,0 +1,4 @@
+- bump: patch
+  changes:
+    fixed:
+    - Montana 2023 / 2024 EITC match.

policyengine_us/parameters/gov/states/mt/tax/income/credits/eitc/rate.yaml → policyengine_us/parameters/gov/states/mt/tax/income/credits/eitc/match.yaml

@@ -1,14 +1,18 @@
 description: Montana matches this fraction of the federal earned income tax credit.
 values:
   2021-01-01: 0.03
-  2023-01-01: 0.10
+  2024-01-01: 0.10
 metadata:
   unit: year
-  label: Montana EITC rate
+  period: year
+  label: Montana EITC match
   reference:
     - title: Montana Code 2021, § 15-30-2318 (2), Earned income tax credit  
       href: https://law.justia.com/codes/montana/2021/title-15/chapter-30/part-23/section-15-30-2318/
     - title: Montana Code 2022, § 15-30-2318 (2), Earned income tax credit  
       href: https://law.justia.com/codes/montana/2022/title-15/chapter-30/part-23/section-15-30-2318/
+    # The amendment applies in 2024
     - title: Montana Code 2023, § 15-30-2318 (2), Earned income tax credit 
       href: https://leg.mt.gov/bills/mca/title_0150/chapter_0300/part_0230/section_0180/0150-0300-0230-0180.html
+    - title: 2023 Monatana Form 2 Individual Income Tax Instructions, line 23b
+      href: https://mtrevenue.gov/wp-content/uploads/dlm_uploads/2023/12/Form_2_2023.pdf#page=1

policyengine_us/tests/policy/baseline/gov/states/mt/tax/income/credits/mt_eitc.yaml

@@ -12,7 +12,7 @@
     eitc: 1_000
     state_code: MT
   output: 
-    mt_eitc: 100
+    mt_eitc: 30
 
 - name: 2022 EITC from federal (test 2)
   period: 2022
@@ -40,3 +40,11 @@
         state_code: MT
   output:
     mt_eitc: [30, 0]
+
+- name: 2024 10% EITC match
+  period: 2024
+  input:
+    eitc: 1_000
+    state_code: MT
+  output: 
+    mt_eitc: 100

policyengine_us/variables/gov/states/mt/tax/income/credits/mt_eitc.py

@@ -12,11 +12,11 @@ class mt_eitc(Variable):
 
     def formula(person, period, parameters):
         federal_eitc = person.tax_unit("eitc", period)
-        rate = parameters(period).gov.states.mt.tax.income.credits.eitc.rate
+        p = parameters(period).gov.states.mt.tax.income.credits.eitc
         # Since the eitc amount can be attributed to either spouse, we will allocate the
         # value to the head
         is_head = person("is_tax_unit_head", period)
-        state_eitc = federal_eitc * rate
+        state_eitc = federal_eitc * p.match
         # Separate filers are inleigible for the Montana EITC, this case is currently
         # excluded as we only model separate filing on the same return
         return is_head * state_eitc