a06e1c6545
before this change, when running `scylla-housekeeping`:
```
/opt/scylladb/scripts/libexec/scylla-housekeeping:122: SyntaxWarning: invalid escape sequence '\s'
match = re.search(".*http.?://repositories.*/scylladb/([^/\s]+)/.*/([^/\s]+)/scylladb-.*", line)
```
we could have the warning above. because `\s` is not a valid escape
sequence, but the Python interpreter accepts it as two separated
characters of `\s` after complaining. but it's still annoying.
so, let's use a raw string here.
Refs scylladb/scylladb#20317
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closes scylladb/scylladb#20359