Update rules_pkg to the latest release.

[aiuto]

PR Checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• Other... Please describe:

What is the current behavior?

pkg_tar is being referenced at a legacy location (@rules_pkg//:pkg.bzl) which will go away in a future release of rules_pkg. This PR updates rules_pkg to the latest release and fixes the references to be to the correct location (@rules_pkg//pkg:tar.bzl) which will remain correct indefinitely.

Issue Number: N/A

What is the new behavior?

Does this PR introduce a breaking change?

• Yes
• No

Other information

[uhthomas]

Looks good, though we may be using an old version of rules_pkg by the looks of it.

(14:33:39) ERROR: error loading package 'testdata': Label '@rules_pkg//pkg:tar.bzl' is invalid because 'pkg' is not a package; perhaps you meant to put the colon here: '@rules_pkg//:pkg/tar.bzl'?

[aiuto]

Fixed.
I updated to the latest rules_pkg, and fixed the tests which were depending on the ancient, broken, behavior of adding a '.' folder to every tarball.

[aiuto]

Friendly ping