Fix for some arm64 machines.
Fix for some arm64 machines.

As said in GoogleContainerTools/distroless#657, in the past, distroless/base:debug used an arm32 busybox binary in its arm64 image. Which doesn't work on some arm64 machines, e.g., Ubuntu 21 arm64 on Parallel Desktop on Apple Silicon M1. It caused this error:
"
$ docker run -it gcr.io/distroless/base@sha256:cfdc553400d41b47fd231b028403469811fcdbc0e69d66ea8030c5a0b5fbac2b
standard_init_linux.go:228: exec user process caused: exec format error
"

This PR GoogleContainerTools/distroless#960 fixes this bug. Hence, update the distroless/base:debug used by Tekton Pipeline in this commit.

tektoncd/pipeline,tektoncd/pipeline