Deduplicate test cases in generator (#4706)

This is a bandaid fix for #4705.

Author: jtraglia

tests/core/pyspec/eth2spec/gen_helpers/gen_base/gen_runner.py

@@ -130,9 +130,23 @@ def debug_print(msg):
     # Gracefully handle Ctrl+C
     install_sigint_handler(console)
 
+    # Deduplicate test cases based on identifier
+    input_test_cases_list = list(input_test_cases)
+    seen_identifiers = {}
+    deduplicated_test_cases = []
+    for test_case in input_test_cases_list:
+        identifier = test_case.get_identifier()
+        if identifier not in seen_identifiers:
+            seen_identifiers[identifier] = True
+            deduplicated_test_cases.append(test_case)
+
+    debug_print(f"Total test cases before deduplication: {len(input_test_cases_list)}")
+    debug_print(f"Total test cases after deduplication: {len(deduplicated_test_cases)}")
+    debug_print(f"Duplicates removed: {len(input_test_cases_list) - len(deduplicated_test_cases)}")
+
     total_found = 0
     selected_test_cases = []
-    for test_case in input_test_cases:
+    for test_case in deduplicated_test_cases:
         total_found += 1
         # Check if the test case should be filtered out
         if len(args.runners) != 0 and test_case.runner_name not in args.runners: