feat: add codspeed for continuous benchmarking

[erikwrede]

This PR adds CodSpeed for benchmarking

[codspeed-hq]

CodSpeed Performance Report

Congrats! CodSpeed is installed 🎉

🆕 14 new benchmarks were detected.

You will start to see performance impacts in the reports once the benchmarks are run from your default branch.

Detected benchmarks

• test_execute_async_iterable_list_field (12 ms)
• test_build_schema_from_ast (109.7 ms)
• test_build_schema_from_introspection (127.2 ms)
• test_execute_basic_async (2.8 ms)
• test_execute_basic_sync (2.7 ms)
• test_recreate_a_graphql_schema (13.5 ms)
• test_execute_introspection_query (820 ms)
• test_parse_kitchen_sink (7.4 ms)
• test_many_repeated_fields (650.8 ms)
• test_validate_introspection_query (15.6 ms)
• test_validate_invalid_query (188.5 ms)
• test_validate_sdl_document (454.6 ms)
• test_visit_all_ast_nodes (213.1 ms)
• test_visit_all_ast_nodes_in_parallel (1.5 s)

[Cito]

Thanks, looks good. I have made two comments. I'd also move it into a separate yml file.

You can ignore the mypy issues since they are not related to the PR, I fill fix them in main.