Add #![warn(clippy::pedantic)] to lib.rs and main.rs files

We already enforced pedantic clippy lints via the
following command in .github/workflows/ci.yaml:

    cargo clippy --workspace --all-targets --all-features -- -D warnings -W clippy::pedantic

Additionally adding #![warn(clippy::pedantic)] to all main.rs and lib.rs
has the benefit that violations of pedantic clippy lints are also
reported when just running `cargo clippy` without any arguments and
are thereby also picked up by LSP[1] servers such as rust-analyzer[2].
However for rust-analyzer to run clippy you'll have to configure:

    "rust-analyzer.check.command": "clippy",

in your editor.[3]

[1]: https://microsoft.github.io/language-server-protocol/
[2]: https://rust-analyzer.github.io/
[3]: https://rust-analyzer.github.io/manual.html#configuration

ruff_dev/src/main.rs

@@ -2,6 +2,7 @@
 //!
 //! Within the ruff repository you can run it with `cargo dev`.
 #![forbid(unsafe_code)]
+#![warn(clippy::pedantic)]
 #![allow(
     clippy::collapsible_else_if,
     clippy::collapsible_if,