semgrep: Add rule to enforce no use of stream.objects.filter.

tools/linter_lib/custom_check.py

@@ -390,10 +390,6 @@ python_rules = RuleList(
          },
          'description': 'Please use access_stream_by_*() to fetch Stream objects',
          },
-        {'pattern': 'Stream.objects.filter',
-         'include_only': {"zerver/views/"},
-         'description': 'Please use access_stream_by_*() to fetch Stream objects',
-         },
         {'pattern': '^from (zerver|analytics|confirmation)',
          'include_only': {"/migrations/"},
          'exclude': {

tools/semgrep.yml

@@ -18,3 +18,11 @@ rules:
     message: "Useless if statment; both blocks have the same body"
     languages: [python]
     severity: ERROR
+
+  - id: dont-use-stream-objects-filter
+    pattern: Stream.objects.filter(...)
+    message: "Please use access_stream_by_*() to fetch Stream objects"
+    languages: [python]
+    severity: ERROR
+    paths:
+      - directory: "zerver/views/"