feat: add full support for TOML 1.1

[Hofer-Julian]

Description

Fixes #6387

How Has This Been Tested?

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Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added sufficient tests to cover my changes.
• I have verified that changes that would impact the JSON schema have been made in schema/model.py.

[hunger]

You seem to have covered the success-cases very successfully. Good work:-)

I think I found some corner-cases that still need fixing.

Take a look at this pixi.toml:

[workspace]
platforms = ["linux-64",
  # penguins!
  "win-64"]
channels = ["https://repo.example-com/ch/"]

dependencies = { numpy = "*",
  # more penguins
  scipy = "*" }

This command breaks the file: pixi workspace platform remove win-64. I think pixi remove scipy would also result in a broken file, but I get an error when I try on this syntax (works in "classic" syntax).

pixi workspace channel remove https://repo.example.com/ch/ (note: Exactly matches the toml file) fails to remove the channel with an error stating it does not exist. That looks like a normalization problem, those usually bring their friends :-)

Doing pixi w platform remove win-64 in this setup

platforms = [
  "linux-64", # penguins!
  "win-64"
]

removes the comment penguins! that obviously belongs to Linux. I had expected that to be kept in this setup.

I did miss e.g. feature removal. Is that covered already? Should that be covered?