fix add profile conditions

[Casheeew]

This change resolves #414 .
I believe this bug is caused by #364 . However, I am not sure if this solution captures every instance caused by this change.
@toasted-nutbread thoughts?

[github-actions]

✔️ No visual differences introduced by this PR.

View Playwright Report (note: open the "playwright-report" artifact)

[toasted-nutbread]

Presumably this is due to elements not existing in certain contexts. If that's the case, mark the type as nullable and omit the cast.

/** @type {?HTMLButtonElement} */
this._menuButton = this._node.querySelector('.profile-condition-menu-button');

[toasted-nutbread]

That being said, this is probably another case of legacy code never being fully removed. If you search for profile-condition-remove in the codebase, it only comes up in one place: the code that is being modified here. This indicates that the element actually doesn't exist, and all codepaths involving this field should just be deleted.

[toasted-nutbread]

For _conditionContainer, you can leave that as the NotNull version and just remove any subsequent null checks. Same for _menuButton.

The reason these dead codepaths and unnecessary checks exist is because there was a massive UI overhaul of the settings page a long time ago, and the same classes would drive both versions of the settings page for the time they co-existed.

[Casheeew]

Thanks. I included the changes.