Merge branch 'jk/pack-tag-of-tag' into maint

"git pack-objects --include-tag" was taught that when we know that we are sending an object C, we want a tag B that directly points at C but also a tag A that points at the tag B. We used to miss the intermediate tag B in some cases. * jk/pack-tag-of-tag: pack-objects: walk tag chains for --include-tag t5305: simplify packname handling t5305: use "git -C" t5305: drop "dry-run" of unpack-objects t5305: move cleanup into test block