Mops up some required updates to the release script/process that were missed for v50
Changeset
Bumped release image to Node 18
Removed deprecated lerna bootstrap command from release script and package.json
Added packages config to lerna to exclude the test fixture from lerna operations - the test fixture is already a private package so doesn't get published, but this prevents lerna bumping the test fixture dependencies on release, which we don't want to do as we always want to use the latest packages directly from the monorepo
Goal
Mops up some required updates to the release script/process that were missed for v50
Changeset
packagesconfig to lerna to exclude the test fixture from lerna operations - the test fixture is already a private package so doesn't get published, but this prevents lerna bumping the test fixture dependencies on release, which we don't want to do as we always want to use the latest packages directly from the monorepo