When running bin/bootstrap, the following error is seen on RHEL9:

+ tox -e py3 -n
usage: tox [--version] [-h] [--help-ini] [-v] [-q] [--showconfig] [-l] [-a] [-c CONFIGFILE] [-e envlist] [--devenv ENVDIR] [--notest] [--sdistonly] [--skip-pkg-install] [-p [VAL]] [-o]
[--parallel--safe-build] [--installpkg PATH] [--develop] [-i URL] [--pre] [-r] [--result-json PATH] [--discover PATH [PATH ...]] [--hashseed SEED] [--force-dep REQ]
[--sitepackages] [--alwayscopy] [--no-provision [REQUIRES_JSON]] [-s [val]] [--workdir PATH]
[args ...]
tox: error: unrecognized arguments: -n
+ catch

The tox -n flag is not available in RHEL9.  Instead use the --no-test flag which is valid in both Fedora and RHEL.