ci: run clippy w/ --all-targets

This ensures test code is also linted.

.github/workflows/test.yaml

@@ -181,7 +181,7 @@ jobs:
         # (below) will have a new lint that we want to suppress.
         # If we suppress (e.g. #![allow(clippy::arc_with_non_send_sync)]),
         # we would get an unknown-lint error from older clippy versions.
-        run: cargo clippy --locked --workspace -- -D warnings -A unknown-lints
+        run: cargo clippy --locked --workspace --all-targets -- -D warnings -A unknown-lints
 
   clippy-nightly-optional:
     name: Clippy nightly (optional)
@@ -196,7 +196,7 @@ jobs:
         with:
           components: clippy
       - name: Check clippy
-        run: cargo clippy --locked --workspace -- -D warnings
+        run: cargo clippy --locked --workspace --all-targets -- -D warnings
 
   clang-tidy:
     name: Clang Tidy