fix: Run income-tax-slab patch only if slab already exists in payroll period (#21684)

diff --git a/erpnext/patches/v13_0/move_tax_slabs_from_payroll_period_to_income_tax_slab.py b/erpnext/patches/v13_0/move_tax_slabs_from_payroll_period_to_income_tax_slab.py
index 179be2c..ec94cd0 100644
--- a/erpnext/patches/v13_0/move_tax_slabs_from_payroll_period_to_income_tax_slab.py
+++ b/erpnext/patches/v13_0/move_tax_slabs_from_payroll_period_to_income_tax_slab.py
@@ -7,7 +7,7 @@
 from frappe.model.utils.rename_field import rename_field
 
 def execute():
-	if not frappe.db.table_exists("Payroll Period"):
+	if not (frappe.db.table_exists("Payroll Period") and frappe.db.table_exists("Taxable Salary Slab")):
 		return
 
 	for doctype in ("income_tax_slab", "salary_structure_assignment", "employee_other_income", "income_tax_slab_other_charges"):
@@ -60,6 +60,9 @@
 				""", (income_tax_slab.name, company.name, period.start_date))
 
 	# move other incomes to separate document
+	if not frappe.db.table_exists("Employee Tax Exemption Proof Submission"):
+		return
+
 	migrated = []
 	proofs = frappe.get_all("Employee Tax Exemption Proof Submission",
 		filters = {'docstatus': 1},
@@ -79,6 +82,9 @@
 			except:
 				pass
 
+	if not frappe.db.table_exists("Employee Tax Exemption Declaration"):
+		return
+
 	declerations = frappe.get_all("Employee Tax Exemption Declaration",
 		filters = {'docstatus': 1},
 		fields =['payroll_period', 'employee', 'company', 'income_from_other_sources']