[bug] Inconsistent output of conan create lock

[rconde01]

Describe the bug

conan_override_null.zip
In creating a lockfile with from a recipe with an override, I'm seeing sometimes the output is:

    "overrides": {
        "sqlite3/3.44.2": [
            "sqlite3/3.45.0#3a7911478ffd14e7acc694ac113449b6"
        ],
        "sqlite3/3.45.0": [
            "sqlite3/3.45.0#3a7911478ffd14e7acc694ac113449b6",
            null
        ]
    },

and sometimes the output is:

    "overrides": {
        "sqlite3/3.44.2": [
            "sqlite3/3.45.0#3a7911478ffd14e7acc694ac113449b6"
        ],
        "sqlite3/3.45.0": [
            null,
            "sqlite3/3.45.0#3a7911478ffd14e7acc694ac113449b6"
        ]
    },

I've also seen where it gets to:

        "sqlite3/3.45.0#3a7911478ffd14e7acc694ac113449b6": [
            null,
            "sqlite3/3.45.0#3a7911478ffd14e7acc694ac113449b6"
        ]

but i didn't see that in this reproduction.

How to reproduce it

1. Extra the zip
2. Run test.py (it will automatically create a virtual environment and install conan)
3. Look at the output test_deps.lock
4. It will randomly switch between the 2 configurations

[rconde01]

BTW I'm considering post processing the file for consistency - but i'm not sure if these configurations have a certain semantic difference - I didn't find any documentation on the lock file itself.