chore(deps): bump faker from 8.1.4 to 13.12.1

Faker is a dev dependency installed for tests - to access the
frappe.mock API to generate paragraphs, names & emails.

dev-requirements.txt

@@ -1,4 +1,4 @@
 coverage==5.5
-Faker~=8.1.0
+Faker~=13.12.1
 pyngrok~=5.0.5
 unittest-xml-reporting~=3.0.4