Modernize CodSpeed integration with OIDC authentication

[codspeed-hq]

Summary

This PR modernizes the CodSpeed integration by migrating from legacy token-based authentication to the recommended OpenID Connect (OIDC) authentication method.

Key Changes

• OIDC Authentication: Migrated from token parameter to OIDC-based authentication using id-token: write permissions
• Simulation Mode: Changed from instrumentation mode to simulation mode for more consistent and accurate performance measurements
• Python Version: Updated benchmark workflow to use Python 3.14 (from 3.13) to align with the project's latest supported version
• Badge Enhancement: Added utm_source parameter to the CodSpeed badge URL for better tracking

Benefits

• Improved Security: OIDC authentication is more secure and doesn't require managing secret tokens
• Better Performance Data: Simulation mode provides more consistent measurements by isolating from environmental noise
• Future-proof: Uses the latest recommended practices from CodSpeed documentation

Test Plan

• Verify that the Performance workflow runs successfully on this PR
• Confirm that benchmark results are reported to CodSpeed
• Check that the CodSpeed badge updates correctly
• Ensure all existing benchmarks continue to work as expected

The workflow will automatically run when this PR is created and should successfully report benchmark results to CodSpeed using the new OIDC authentication method.

[codspeed-hq]

CodSpeed Performance Report

Congrats! CodSpeed is installed 🎉

🆕 18 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_pickle_large_query_encode: 56.7 ms
• test_build_schema_from_ast: 111.3 ms
• test_execute_basic_async: 2.6 ms
• test_validate_invalid_query: 104.1 ms
• test_visit_all_ast_nodes_in_parallel: 1.7 s
• test_build_schema_from_introspection: 121.8 ms
• test_execute_introspection_query: 980.6 ms
• test_execute_basic_sync: 2.5 ms
• test_pickle_large_query_roundtrip: 95.1 ms
• test_validate_introspection_query: 16.1 ms
• test_parse_large_query: 237.1 ms
• test_execute_async_iterable_list_field: 14.4 ms
• test_many_repeated_fields: 264.6 ms
• test_pickle_large_query_decode: 38.7 ms
• test_recreate_a_graphql_schema: 13.4 ms
• test_validate_sdl_document: 456.4 ms
• test_visit_all_ast_nodes: 219.9 ms
• test_parse_kitchen_sink: 4.4 ms