Parallelize symlinks

Improve sapling behavior with devel packages

* If no bookmarks are found, consider always the same branchOrRef,
  as if you where on a branch called "none".
* If a bookmark is there, use the bookmark as identifier for branchOrRef.

Auto prune on fetch

Fixes situations like the remote repository deleting a branch `a` and
creating a branch `a/b`. Otherwise we have situations like the
following:

```
error: cannot lock ref 'refs/remotes/origin/a/b': 'refs/remotes/a' exists; cannot create 'refs/remotes/origin/a/b'
```

Solution adapted from https://stackoverflow.com/a/67060742/20041091

Revert "Fix the license metadata"

This reverts commit d0b6a70.

Fix the license metadata

Fix multiline env variables

Regression in #947

Sanitize getRetry

Escape fetching of symlinks (#953)

Log the time it takes to upload the symlinks (#952)

Load CLI environment variables in prefer_system_check (#947)