Update meta.yaml for release of v4.3.1

addressing #211 (possibility of missing lookup when calling `op_in_dr…

…essed_eigenbasis`)

prep for 4.2 release

version number increase; getting ready for release

updated version to 4.0.0 for new release

black

Issue one-time warning if fixed InteractionTerm operators are used

typo fix

forward to v3.1

forward to v3.0.3