Cheers rang out outside Bangkok’s Klong Prem prison on Thursday as Thailand’s billionaire former prime minister Thaksin Shinawatra walked free on parole, eight months after a court ordered him to serve prison time he had earlier avoided through an extended stay in hospital. Now 76, the business magnate spent a quarter-century reshaping and dominating Thai politics. Yet his grip on the country’s political landscape has weakened in recent months after his jailing and after his once-powerful Pheu Thai Party suffered its…