Simplify distro/release

[alexeagle]

From bazel-contrib/SIG-rules-authors#11 I learned that it's overkill for us to build a distribution artifact.

The only reasons to bother are:

• users can bazel query @aspect_bazel_lib//... and not trip on our load() statement from stardoc. But users ~never do that.
• the distribution is smaller since docs and tests aren't included. But we're talking dozens of kilobytes which isn't worth the complexity.

All my remaining reasons for it turned out to be wrong. Trying the simplification here.

Proof of what we need to do when generating a workspace snippet:

alexeagle@system76-pc:~/Projects/bazel-lib$ git archive --format=tar --prefix=bazel-lib-0.2.7/ v0.2.7 | gzip > /tmp/tarball.tgz; sha256sum /tmp/tarball.tgz
ce379ba06f861f5cab773862fc8eaeff3a531e744e2076165f4bbef4cb7ac046  /tmp/tarball.tgz

alexeagle@system76-pc:~/Projects/bazel-lib$ curl -L https://github.com/aspect-build/bazel-lib/archive/v0.2.7.tar.gz|sha256sum -
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   130  100   130    0     0    431      0 --:--:-- --:--:-- --:--:--   430
100 29335    0 29335    0     0  43588      0 --:--:-- --:--:-- --:--:-- 43588
ce379ba06f861f5cab773862fc8eaeff3a531e744e2076165f4bbef4cb7ac046  -

/cc @cgrindel