Pin the version of Delve in the debug images #5850
Description
In docker/debug/Dockerfile we are always installing the latest delve
go install github.com/go-delve/delve/cmd/dlv@latest
A better solution (for repeatable builds) is to have a local go.mod file that can be managed by the bots for version upgrades, similar to how we do it for tools in internal/tools.