Filter pkg with tests in parallel

tools/flakeguard/golang/golang.go

@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"os/exec"
 	"strings"
+	"sync"
 
 	"github.com/smartcontractkit/chainlink-testing-framework/tools/flakeguard/utils"
 )
@@ -185,14 +186,26 @@ func hasTests(pkgName string) (bool, error) {
 // Filter out test packages with no actual test functions
 func FilterPackagesWithTests(pkgs []string) []string {
 	var testPkgs []string
+	var mutex sync.Mutex
+	var wg sync.WaitGroup
+
 	for _, pkg := range pkgs {
-		hasT, err := hasTests(pkg)
-		if err != nil {
-			fmt.Printf("Error checking for tests in package %s: %s\n", pkg, err)
-		}
-		if hasT {
-			testPkgs = append(testPkgs, pkg)
-		}
+		wg.Add(1)
+		go func(p string) {
+			defer wg.Done()
+			hasT, err := hasTests(p)
+			if err != nil {
+				fmt.Printf("Error checking for tests in package %s: %s\n", p, err)
+				return
+			}
+			if hasT {
+				mutex.Lock()
+				testPkgs = append(testPkgs, p)
+				mutex.Unlock()
+			}
+		}(pkg)
 	}
+
+	wg.Wait()
 	return testPkgs
 }