Squash warning after embed-resource version bump; enable clippy in ci

[alsuren]

I just pulled main and got:

warning: unused `embed_resource::CompilationResult` that must be used
 --> cargo-quickinstall/build.rs:6:5
  |
6 |     embed_resource::compile("manifest.rc", embed_resource::NONE);
  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  |
  = note: `-D unused-must-use` implied by `-D warnings`
  = help: to override `-D warnings` add `#[allow(unused_must_use)]`
help: use `let _ = ...` to ignore the resulting value
  |
6 |     let _ = embed_resource::compile("manifest.rc", embed_resource::NONE);
  |     +++++++

warning: `cargo-quickinstall` (build script) generated 1 warning
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.96s

This seems like it was caused by #319 and not caught by our CI.

I also ran clippy in the stats-server project and found another warning.