pgxpool: only assert the lower bound of the ShouldPing idle duration

TestPoolAcquireChecksIdleConnsWithShouldPing released a connection, slept 200ms, and then required the idle duration
reported to ShouldPing to be within 100ms of the sleep. A loaded CI runner can delay the acquire well past the sleep,
and the test failed with an idle duration of 317.5ms. Only the lower bound is meaningful, so assert that instead.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

Author: jackc

pgxpool/pool_test.go

@@ -235,19 +235,23 @@ func TestPoolAcquireChecksIdleConnsWithShouldPing(t *testing.T) {
 	require.NoError(t, err)
 	defer pool.Close()
 
+	const idleTime = 200 * time.Millisecond
+
 	c, err := pool.Acquire(ctx)
 	require.NoError(t, err)
 	c.Release()
 
-	time.Sleep(time.Millisecond * 200)
+	time.Sleep(idleTime)
 
 	c, err = pool.Acquire(ctx)
 	require.NoError(t, err)
 	conn := c.Conn()
 
 	require.NotNil(t, shouldPingLastCalledWith)
 	assert.Equal(t, conn, shouldPingLastCalledWith.Conn)
-	assert.InDelta(t, time.Millisecond*200, shouldPingLastCalledWith.IdleDuration, float64(time.Millisecond*100))
+	// Only the lower bound can be asserted. A busy machine can delay the acquire arbitrarily long after the sleep,
+	// which made an upper bound assertion flaky in CI.
+	assert.GreaterOrEqual(t, shouldPingLastCalledWith.IdleDuration, idleTime)
 
 	c.Release()
 }