Parsing fails for `Cargo.toml` with profile

[ggwpez]

Feels more like a DQ to me; Parsing a Cargo.toml with a profile fails (eg. Substrates'):

[workspace]

members = [ ]

[profile.production]
inherits = "release"

results in:

$ cargo unleash --manifest-path Cargo.toml em-dragons
Error: "Reading workspace \"Cargo.toml\" failed: failed to parse manifest at `Cargo.toml`

It works fine without the profile definition.