validate configuration options explicitly

When handling configuration options or tool types, use explicit conditional statements with proper error handling for unknown values instead of implicit fallbacks or else clauses. This prevents silent failures and makes it clear which configurations are supported.

Use elif statements for each known configuration option and include an assert False or explicit error for unhandled cases:

if self.tool == "llama-bench":
    self.check_keys = set(LLAMA_BENCH_KEY_PROPERTIES + ["build_commit", "test_time", "avg_ts"])
elif self.tool == "test-backend-ops":
    self.check_keys = set(TEST_BACKEND_OPS_KEY_PROPERTIES + ["build_commit", "test_time"])
else:
    assert False, f"Unknown tool type: {self.tool}"

This approach helps catch configuration errors early, makes the supported options explicit in the code, and prevents issues like duplicate settings or silent overwrites that can occur with implicit handling. When adding new configuration options, developers must explicitly update the validation logic, ensuring all cases are properly considered.