This is safe, because while the annex object ends up executable,
there were already at least two other cases where it ended up executable:
1. git add an an executable file
2. chmod +x of a a non-executable worktree file that was hard linked to the
annex object
After copy/hard link, it always fixes up the permissions to match the mode
of the worktree file, so when an executable annex object gets hard linked
to a non-executable worktree file, its execute bit gets removed.
Commit b7c8bf5274 already *said* it would do
this; I suspect the line of code I've removed was included in that commit
accidentially.
Also improves annex.thin documentation.
This commit was sponsored by Boyd Stephen Smith Jr. on Patreon.