pw_work_queue: clang-tidy fix

Get bazelisk build --config=clang-tidy //pw_work_queue/... to pass.

Change-Id: I8cc77bb58b1fa23d5fb10ec9f8fd0d2c4b09381e
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/262192
Docs-Not-Needed: Ted Pudlik <tpudlik@google.com>
Lint: Lint 🤖 <android-build-ayeaye@system.gserviceaccount.com>
Reviewed-by: Dave Roth <davidroth@google.com>
Reviewed-by: Rob Mohr <mohrr@google.com>
Commit-Queue: Ted Pudlik <tpudlik@google.com>

pw_work_queue/BUILD.bazel

@@ -46,6 +46,7 @@ cc_library(
     name = "test_thread_header",
     hdrs = ["public/pw_work_queue/test_thread.h"],
     strip_include_prefix = "public",
+    deps = ["//pw_thread:thread"],
 )
 
 cc_library(