fix(timing): Do not resume timing in pause scope on skipped benchmarks (#2318)

Currently, skipping a benchmark with an error from a `ScopedPauseTiming` fails
with GB built in debug mode, since `ResumeTiming()` is called outside of a benchmark
loop.

This mirrors the logic in `State::FinishKeepRunning()`, which pauses only if the
benchmark was not skipped. Leaving the timer paused is preferable to resuming after
a skip, which could then also corrupt timings.

include/benchmark/state.h

diff --git a/include/benchmark/state.h b/include/benchmark/state.h
index 86009e2..69c4211 100644
--- a/include/benchmark/state.h
+++ b/include/benchmark/state.h
@@ -282,7 +282,9 @@
   explicit ScopedPauseTiming(State& state) : state_(state) {
     state_.PauseTiming();
   }
-  ~ScopedPauseTiming() { state_.ResumeTiming(); }
+  ~ScopedPauseTiming() {
+    if (!state_.skipped()) state_.ResumeTiming();
+  }
 
   ScopedPauseTiming(const ScopedPauseTiming&) = delete;
   void operator=(const ScopedPauseTiming&) = delete;