Issue #3246760 by VladimirAus: Update library to 4.6.1

_SUBTHEME/scss/overrides/_variables.scss

bootstrap4.info

composer.json

css/style.css

css/style.css.map

dist/bootstrap/4.4.1/.eslintrc.json

dist/bootstrap/4.4.1/.github/ISSUE_TEMPLATE/bug.md

dist/bootstrap/4.4.1/.github/ISSUE_TEMPLATE/feature.md

dist/bootstrap/4.4.1/.github/workflows/test.yml

dist/bootstrap/4.4.1/Gemfile

dist/bootstrap/4.4.1/Gemfile.lock

dist/bootstrap/4.4.1/_config.yml

dist/bootstrap/4.4.1/build/change-version.js

dist/bootstrap/4.4.1/build/postcss.config.js

dist/bootstrap/4.4.1/build/ship.sh

dist/bootstrap/4.4.1/dist/css/bootstrap-grid.css.map

dist/bootstrap/4.4.1/dist/css/bootstrap-grid.min.css

dist/bootstrap/4.4.1/dist/css/bootstrap-grid.min.css.map

dist/bootstrap/4.4.1/dist/css/bootstrap-reboot.css.map

dist/bootstrap/4.4.1/dist/css/bootstrap-reboot.min.css