ci: semgrep to prevent test regression

semgrep/test-correctness.yml

@@ -0,0 +1,18 @@
+rules:
+- id: Dont-commit
+  pattern: frappe.db.commit()
+  message: Commiting inside test breaks idempotency.
+  languages: [python]
+  severity: ERROR
+- id: Implicit-commit
+  pattern: frappe.db.truncate()
+  message: DB truncation does implict commit which breaks test idempotency.
+  languages: [python]
+  severity: ERROR
+- id: Dont-override-teardown
+  pattern: |
+    def tearDown(...):
+      ...
+  message: ERPNextTestSuite forces rollback on each tearDown, which ensures idempotency. Don't override tearDown.
+  languages: [python]
+  severity: ERROR