fix: resolve two root causes of vrf v1 nightly race

The scheduled go_core_race_tests job on develop reports three data races
in TestDelegate_InvalidLog. They trace to two independent root causes:

1. core/services/vrf/delegate_test.go double-spawns the v1 listener's
   head and log goroutines. Listener.Start already spawns both
   (listener_v1.go:154-155). The extra goroutines send to the unbuffered
   WaitOnStop channel, which Close drains exactly twice (listener_v1.go:
   519-520), so two goroutines leak per test. A leaked head listener can
   still invoke pipeline.Run → Debugw after t.done=true is written at
   testing.go:2023, racing with the stdlib's deliberately-unsynchronized
   test-completion flag.

2. core/internal/cltest.NewEthMocksWithStartupAssertions omits a
   BalanceAt expectation. The chain's default-enabled BalanceMonitor
   worker calls BalanceAt on the mock while its ctx is being cancelled
   by StopRChan.CtxCancel. Without an expectation, testify's
   m.fail → callString path uses %#v (mock.go:463), which reflects
   through *cancelCtx's unexported atomic.Value fields and races with
   the concurrent atomic stores in (*cancelCtx).cancel. Registering a
   Maybe() expectation routes calls through the happy path, which only
   uses %v via Stringer and never reflects.

Author: Fletch153

core/internal/cltest/cltest.go

@@ -631,6 +631,7 @@ func NewEthMocksWithStartupAssertions(t testing.TB) *clienttest.Client {
 	c.On("CodeAt", mock.Anything, mock.Anything, mock.Anything).Maybe().Return([]byte{}, nil)
 	c.On("NonceAt", mock.Anything, mock.Anything, mock.Anything).Maybe().Return(uint64(0), nil)
 	c.On("PendingNonceAt", mock.Anything, mock.Anything, mock.Anything).Maybe().Return(uint64(0), nil)
+	c.On("BalanceAt", mock.Anything, mock.Anything, mock.Anything).Maybe().Return(big.NewInt(0), nil)
 	c.On("Close").Maybe().Return()
 	c.On("BatchCallContext", mock.Anything, mock.Anything).Maybe().Return(nil)
 

core/services/vrf/delegate_test.go

@@ -198,13 +198,10 @@ func setup(t *testing.T) (vrfUniverse, *v1.Listener, job.Job) {
 	require.NoError(t, err)
 	require.Len(t, vl, 1)
 	listener := vl[0].(*v1.Listener)
-	// Start the listenerV1
-	go func() {
-		listener.RunLogListener([]func(){}, 6)
-	}()
-	go func() {
-		listener.RunHeadListener(func() {})
-	}()
+	// Listener.Start spawns the log and head listener goroutines internally;
+	// manually spawning them again double-spawns and leaks on teardown (Close
+	// drains WaitOnStop exactly twice, so extra goroutines block forever and
+	// their deferred logs can race with testing.T finalization).
 	servicetest.Run(t, listener)
 	return vuni, listener, jb
 }