provisioning: Pin reportlab to 5.0.1 to avoid runtime issues

reportlab is a dependency of sbom2doc.
sbom2doc is used during the sbom build of Qt repos.
The recently released latest version (5.1.0) requires Python 3.10 or
higher.
The module only errors out at runtime when sbom2doc is invoked and the
Python version is lower.

Pin to the previous 5.0.1 version that still works with Python 3.9
which we use on some older platforms like macOS 14.

Pick-to: 6.8 6.12
Change-Id: I51e98eee6973e227946dd7c233eed53dd1f1b219
Reviewed-by: Elias Toivola <elias.toivola@qt.io>