chore: update toml lib to 0.7.6

[cyrinux]

The parsing of my config looks still OK after using last upstream toml version instead of the fork.

[maximbaz]

Looks good indeed, and I remember in particular the fork was needed to parse this kind of config:

[als.time]
thresholds = { 0 = "night", 7 = "dark", 9 = "dim", 11 = "normal", 13 = "bright", 16 = "normal", 18 = "dark", 20 = "night" }

Which is now parsed correctly.

Finally, this PR even fixes #47 😉

Thanks!