LONDON – Wireless carriers in the U.K. won’t be allowed to install Huawei equipment in their high-speed 5G networks after September 2021, the British government said Monday, hardening its line against the Chinese technology company.The deadline is part of a roadmap the British government is laying down to remove “high risk” equipment suppliers with draft legislation that aims to tighten telecommunications security requirements.The government of Prime Minister Boris Johnson in July banned Huawei from having a role in building Britain’s next-generation mobile phone networks over security concerns triggered by U.S.