Restore --all-targets for clippy (#9346)

This PR restores the `--all-targets` flag when running `cargo clippy`.

Without it, there are areas that Clippy does not check, as evidenced by
the violations that were caught once the flag was re-added.

Release Notes:

- N/A

tooling/xtask/src/main.rs

@@ -47,7 +47,10 @@ fn run_clippy(args: ClippyArgs) -> Result<()> {
         clippy_command.arg("--workspace");
     }
 
-    clippy_command.arg("--release").arg("--all-features");
+    clippy_command
+        .arg("--release")
+        .arg("--all-targets")
+        .arg("--all-features");
 
     if args.fix {
         clippy_command.arg("--fix");