Describe the bug

When conan config upgrade ... --update-config-requires '<config_requires>' is run, and conan.lock already contains locked <config_requires> it will be removed and never upgraded.

How to reproduce it

• create conan.lock with a locked config requires (can be fake package)

{
    "version": "0.5",
    "config_requires": [
        "my_config/0.1@user"
    ]
}

• run for example conan config upgrade --requires 'zlib/[*]' --lockfile conan.lock --lockfile-out new_lock.lock --update-config-requires ''my_config/[*]@user'
• notice new_lock.lock's config_requires is empty

{
    "version": "0.5",
    "requires": [
        "zlib/1.3.1#99d6f9ea0a1dd63d973392c24ce0aa9b%1740061896.919"
    ],
    "build_requires": [],
    "python_requires": [],
    "config_requires": []
}

It looks like conan/cli/commands/lock.py:212 removes it from lockfile and it's never generated in subsequent graph resolvement.