On May 8, 2022,.NET 5.0 will be decommissioned. Microsoft will no longer provide service updates for.NET 5.0 after the May upgrades, including security fixes and technical support. To continue receiving updates, you’ll need to update your.NET version to a supported version (.NET 6.0) before this date.
Because.NET 5.0 is not an LTS version, it will be supported for 18 months or until the next release is released, whichever comes first. Support for.NET 5.0 will be phased out on May 8, 2022.
You can check Microsoft Support Policy for more Information: Microsoft Offical Site