In an ideal world, we should not validate connections containing
options not valid for the current bond mode. However adding such
restriction now means that during an upgrade to the new NM version
some connections that were valid before become invalid, possibly
disrupting connectivity.

Instead, consider invalid options as a normalizable error and remove
them during normalization.

Converting the setting to a "canonical" form without invalid options
is important for the connection matching logic, where such invalid
options can cause false mismatches.