By Medha Singh and Lisa Pauline Mattackal (Reuters) – Bitcoin miners are making hay while the sun shines. The business has been yanked out of the doldrums by the cryptocurrency’s recent rally – and now mining companies are racing to lock in profits before bitcoin’s “halving”, when rewards for producing the tokens are cut in half. The next halving is expected in April 2024, a process designed to slow the release of bitcoin, whose supply is capped at 21 million – of which 19 million have already been mined. “You’re seeing a lot of urgency to plug rigs in ahead of the halving,” said Gregory Lewis…