Remove stylelint rules that are no longer needed with later versions. (#4303)

.stylelintrc.yaml

hypha/static_src/sass/abstracts/_mixins.scss

hypha/static_src/sass/abstracts/_variables.scss

hypha/static_src/sass/base/_base.scss

hypha/static_src/sass/components/_all-reviews-table.scss

hypha/static_src/sass/components/_all-submissions-table.scss

hypha/static_src/sass/components/_button.scss

hypha/static_src/sass/components/_dashboard-table.scss

hypha/static_src/sass/components/_feed.scss

hypha/static_src/sass/components/_form.scss

hypha/static_src/sass/components/_nprogress.scss

hypha/static_src/sass/components/_projects-table.scss

hypha/static_src/sass/components/_reviews-sidebar.scss

hypha/static_src/sass/components/_select2.scss

hypha/static_src/sass/components/_submission-meta.scss

hypha/static_src/sass/components/_table.scss

hypha/static_src/sass/components/_tabs.scss

hypha/static_src/sass/components/_two-factor.scss

hypha/static_src/sass/print.scss

hypha/static_src/sass/wagtail_users_list.scss