Data Race issue in unit tests run by github pipeline

[bjee19]

Github pipeline unit tests occasionally fail due to Data Race issues.

Examples:

• https://github.com/nginxinc/nginx-gateway-fabric/actions/runs/10908395436/job/30274342711?pr=2568#step:4:5123
• https://github.com/nginxinc/nginx-gateway-fabric/actions/runs/10855036901/job/30126828250?pr=2546#step:4:2771
• https://github.com/nginxinc/nginx-gateway-fabric/actions/runs/10929251093/job/30339638261?pr=2574#step:4:5451

Notes:
Could be related to the parallelization recently added to tests:

• Run tests in parallel #2537
• Run tests in internal/mode/static/state in parallel (1) #2534
• Run tests in internal/mode/static/nginx/config in parallel (2) #2533
• Run tests in internal/mode/static/nginx/config in parallel (1) #2493
• Run tests in internal/framework in parallel (2) #2367
• Run tests in internal/framework in parallel (1) #2362
• Run tests in cmd/ in parallel #2361

May be able to use the go-lang built in race detector: https://go.dev/doc/articles/race_detector

[lucacome]

#2089 has the remaining tests that are not run in parallel because they fail consistently