Use alpine docker image instead of ubuntu

[yanivagman]

Moving to alpine will reduce ~50MB (non compressed) by installing the following packages for "fat" image:

FROM golang:alpine
RUN apk update
RUN apk add clang llvm make gcc libc6-compat coreutils linux-headers musl-dev elfutils-dev libelf-static zlib-static
...

And for "slim" image, will reduce the image size to less than 10MB (non compressed):
FROM alpine
RUN apk update
RUN apk add libc6-compat elfutils-dev
...

Other advantages of moving to alpine:
Faster CI times (as apk update and apk add are much faster than apt parallels),
Smaller attack surface

If we choose to go in this path, we should also statically link tracee as alpine uses musl (standalone tracee binary compiled using alpine will have musl dependency).
Statically linking the code has its own advantages, as it will remove the libc, libelf and zlib dependencies.
Another security advantage if statically linking is that the binary then can't be preloaded