fix: removing unused imports (#23633)

diff --git a/erpnext/projects/report/billing_summary.py b/erpnext/projects/report/billing_summary.py
index 0b44e9d..6c3c05f 100644
--- a/erpnext/projects/report/billing_summary.py
+++ b/erpnext/projects/report/billing_summary.py
@@ -6,7 +6,6 @@
 import frappe
 from frappe import _
 from frappe.utils import time_diff_in_hours, flt
-from frappe.model.meta import get_field_precision
 
 def get_columns():
 	return [