fix: register HookExecutors in service hooks validation test

The Test_ServiceHooks_ValidationUsesServicePath test from main was missing
the registerHookExecutors call needed for IoC resolution of HookExecutor.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: wbreza

cli/azd/cmd/middleware/hooks_test.go

@@ -304,6 +304,7 @@ func Test_ServiceHooks_Registered(t *testing.T) {
 
 func Test_ServiceHooks_ValidationUsesServicePath(t *testing.T) {
 	mockContext := mocks.NewMockContext(context.Background())
+	registerHookExecutors(mockContext)
 	azdContext := createAzdContext(t)
 
 	envName := "test"