tidb config doesn't take effects when there are invalid config

[guo-shaoge]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

1. write config like

  global:
    user: "guojiangtao"
    ssh_port: 22
    deploy_dir: "/home/guojiangtao/work/tiup_cluster/s3/data/deploy"
    data_dir: "/home/guojiangtao/work/tiup_cluster/s3/data/data"
    arch: "amd64"

  server_configs:
    tidb:
      mem-quota-query: 1073741824
      log.file.max-backups: 10
      log.file.max-days: 5
      log.slow-threshold: 1000
      disaggregated-tiflash: true
      new_collations_enabled_on_first_bootstrap: false
      oom-action: log
      performance.enforce-mpp: 1
      performance.txn-total-size-limit: 107374182
...

2. tiup cluster setup new cluster
3. check disaggregated-tiflash config: show config where name like '%disagg%'

2. What did you expect to see? (Required)

tidb config is correct

3. What did you see instead (Required)

disaggregated-tiflash config is wrong

4. What is your TiDB version? (Required)

v7.5.0

[guo-shaoge]

Actually tidb should report error because perofrmance.enforce-mpp: 1 should be performance.enforce-mpp: true, but tidb miss checking return error of parsing config, code, which cause the config is default value