Use workspace level lints

[faern]

New in Rust 1.74 is cargo managed linting and workspace level lints. Now when we have bumped our build containers to use newest Rust we can start using these.

This allows us to not explicitly specify deny lints in CI invocations of cargo clippy. It also allows us to not have to repeat wanted lints in every crate (#![deny(rust_2018_idioms)]), something we naturally forgot to do in a bunch of crates already 🤷.

---

This change is 

[dlon]

Reviewed 51 of 51 files at r1, all commit messages.
Reviewable status: all files reviewed, 1 unresolved discussion (waiting on @faern)

---

Cargo.toml line 44 at r1 (raw file):

[workspace.lints.rust]
rust_2018_idioms = "deny"

We could probably use workspace lints in test as well.

---

talpid-core/src/lib.rs line 3 at r1 (raw file):

//! The core components of the talpidaemon VPN client.

#![deny(missing_docs)]

Maybe we should move these remaining lints to the (crate-level) [lints]. If they're possible to combine with workspace = true, that is.

[faern]

Reviewable status: 50 of 63 files reviewed, 1 unresolved discussion (waiting on @dlon)

---

Cargo.toml line 44 at r1 (raw file):

Previously, dlon (David Lönnhager) wrote…

We could probably use workspace lints in test as well.

Done! And "cleaned" up that code to follow the new linting rules ✨ 🧹

---

talpid-core/src/lib.rs line 3 at r1 (raw file):

Previously, dlon (David Lönnhager) wrote…

Maybe we should move these remaining lints to the (crate-level) [lints]. If they're possible to combine with workspace = true, that is.

Sadly not. If I add:

[lints.rust]
missing_docs = "deny"

...to talpid-core/Cargo.toml, then I get:

error: failed to load manifest for workspace member `/build/mullvad-daemon`

Caused by:
  failed to load manifest for dependency `mullvad-relay-selector`

Caused by:
  failed to load manifest for dependency `talpid-core`

Caused by:
  failed to parse manifest at `/build/talpid-core/Cargo.toml`

Caused by:
  cannot override `workspace.lints` in `lints`, either remove the overrides or `lints.workspace = true` and manually specify the lints

You cannot both inherit lints and define your own in cargo.

[faern]

Reviewable status: 50 of 63 files reviewed, all discussions resolved (waiting on @dlon)

---

talpid-core/src/lib.rs line 3 at r1 (raw file):

Previously, faern (Linus Färnstrand) wrote…

Sadly not. If I add:

[lints.rust]
missing_docs = "deny"

...to talpid-core/Cargo.toml, then I get:

error: failed to load manifest for workspace member `/build/mullvad-daemon`

Caused by:
  failed to load manifest for dependency `mullvad-relay-selector`

Caused by:
  failed to load manifest for dependency `talpid-core`

Caused by:
  failed to parse manifest at `/build/talpid-core/Cargo.toml`

Caused by:
  cannot override `workspace.lints` in `lints`, either remove the overrides or `lints.workspace = true` and manually specify the lints

You cannot both inherit lints and define your own in cargo.

Would of course be cool to require documentation on all public items in all crates. But I don't think that's a job for this PR if we decide to go there.

[dlon]

Reviewed 13 of 13 files at r2, all commit messages.
Reviewable status: complete! all files reviewed, all discussions resolved

[faern]

Fixes DES-505