Bug 38359: Update css class

Bug 38359: Update css class

col-sm-offset-* no longer exists in bootstrap 5 and we should use offset-sm-* instead

Test plan:
1) Enable ILLModule sys pref
2) Attempt to create a new ILL request:
http://localhost:8081/cgi-bin/koha/ill/ill-requests.pl?method=create&backend=Standard
3) Notice there is no left offset (as was before bug 35402
4) After creating the request, see the detail page:
http://localhost:8081/cgi-bin/koha/ill/ill-requests.pl?op=illview&illrequest_id=1
5) Verify same issue happens here.
6) Apply patch. Repeat test plan.

Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>