fix: wait for goroutine before TempDir cleanup in process test (#17)

TestProcessTopByCPU_SortRegression spawns a goroutine that writes to
TempDir after 1ms. On Go 1.25+ t.TempDir() cleanup is strict and fails
if the directory is not empty. The goroutine could still be writing
when cleanup starts.

Fix: t.Cleanup(func() { <-done }) ensures goroutine finishes before
TempDir removal.

Co-authored-by: dmitriimaksimovdevelop <227611064+dmitriimaksimovdevelop@users.noreply.github.com>
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: dmitriimaksimovdevelop

internal/collector/process_test.go

@@ -133,10 +133,13 @@ func TestProcessTopByCPU_SortRegression(t *testing.T) {
 	// The collector sleeps for SampleInterval between the two reads. We set the
 	// interval to 5ms and rewrite after 1ms to be sure the overwrite lands
 	// between the two reads.
+	done := make(chan struct{})
 	go func() {
+		defer close(done)
 		time.Sleep(1 * time.Millisecond)
 		buildFakeProcfsPass(t, root, 2)
 	}()
+	t.Cleanup(func() { <-done }) // wait for goroutine before TempDir cleanup
 
 	c := NewProcessCollector(root)
 	cfg := CollectConfig{