fix: ci: Fix paths to binaries in cross-version-config-tests job

The cross-version-config-tests job has never functioned in CI because
the testing framework changed after the testing was completed. To run
the new "named" binary using the old configurations, paths in the test
framework must be updated to point to the location of the new binaries.

Closes #4977

Merge branch '4977-fix-cross-version-config-tests' into 'main'

See merge request isc-projects/bind9!9702