Merged PR 3455: Cleans old Xero KPIs models

# Description

Cleans Xero models for the old KPIs flow, temporary tests and schema entries

# Checklist

- [X] The edited models and dependants run properly with production data.
- [NA] The edited models are sufficiently documented.
- [X] The edited models contain PK tests, and I've ran and passed them.
- [NA] I have checked for DRY opportunities with other models and docs.
- [NA] I've picked the right materialization for the affected models.

# Other

- [ ] Check if a full-refresh is required after this PR is merged.

Related work items: #23760

models/intermediate/xero/schema.yml

@@ -259,68 +259,3 @@ models:
       - name: contact_name
         data_type: character varying
         description: ""
-
-  - name: int_xero__monthly_invoicing_history_by_deal
-    description: |
-      This model contains the historic information regarding invoicing metrics for each deal id. 
-      It's used for the business KPIs in the view by deal id. Data is aggregated at the last
-      day of the month, or up to yesterday if it's the current month.
-    tests:
-      - dbt_utils.unique_combination_of_columns:
-          combination_of_columns:
-            - date
-            - id_deal
-
-    deprecation_date: 2024-11-30
-
-    columns:
-      - name: date
-        data_type: date
-        description: The last day of the month or yesterday for historic invoicing metrics.
-        tests:
-          - not_null
-
-      - name: id_deal
-        data_type: character varying
-        description: Id of the deal associated to the host.
-        tests:
-          - not_null
-
-  - name: int_xero__mtd_invoicing_metrics
-    description: |
-      This model contains the historic information regarding the invoiced and credited metrics 
-      in an aggregated manner. 
-      It's used for the business KPIs. Data is aggregated at the last day of the month and in the
-      days necessary for the Month-to-Date computation of the current month.
-
-    deprecation_date: 2024-11-30
-
-    tests:
-      - dbt_utils.unique_combination_of_columns:
-          combination_of_columns:
-            - date
-            - dimension
-            - dimension_value
-
-    columns:
-      - name: date
-        data_type: date
-        description: The date for the month-to-date invoicing-related metrics.
-        tests:
-          - not_null
-
-      - name: dimension
-        data_type: string
-        description: The dimension or granularity of the metrics.
-        tests:
-          - accepted_values:
-              values:
-                - global
-                - by_number_of_listings
-                - by_billing_country
-
-      - name: dimension_value
-        data_type: string
-        description: The value or segment available for the selected dimension.
-        tests:
-          - not_null