docs: remove the unused static/assets/css/bootstrap.min.css (#1517)

We build Bootstrap ourselves

package.json

@@ -20,15 +20,14 @@
     "start": "npm run docs-serve",
     "docs-serve": "hugo server --port 4000 --disableFastRender",
     "docs-build": "hugo --cleanDestinationDir",
-    "docs-purge": "npm run docs-build && purgecss --css docs/static/assets/css/bootstrap.min.css --content \"_site/**/*.html\" \"_site/assets/js/**/*.js\" --keyframes --output docs/static/assets/css/",
     "pages": "node build/build-pages.js",
     "icons": "npm-run-all icons-main --aggregate-output --parallel icons-sprite icons-font",
     "icons-main": "node build/build-svgs.js",
     "icons-zip": "cross-env-shell \"rm -rf bootstrap-icons-$npm_package_version && cp -r icons/ bootstrap-icons-$npm_package_version && cp bootstrap-icons.svg bootstrap-icons-$npm_package_version && cp -r font/ bootstrap-icons-$npm_package_version && zip -r9 bootstrap-icons-$npm_package_version.zip bootstrap-icons-$npm_package_version && rm -rf bootstrap-icons-$npm_package_version\"",
     "icons-sprite": "svg-sprite --config svg-sprite.json --log=info icons/*.svg",
     "icons-font": "fantasticon",
     "release": "npm-run-all icons docs-build icons-zip",
-    "netlify": "cross-env-shell HUGO_BASEURL=$DEPLOY_PRIME_URL npm-run-all icons docs-purge docs-build",
+    "netlify": "cross-env-shell HUGO_BASEURL=$DEPLOY_PRIME_URL npm-run-all icons docs-build",
     "test:fusv": "fusv docs/assets/scss/",
     "test:eslint": "eslint --cache --cache-location node_modules/.cache/.eslintcache --report-unused-disable-directives .",
     "test:stylelint": "stylelint docs/assets/scss/ --cache --cache-location node_modules/.cache/.stylelintcache --rd",
@@ -51,7 +50,6 @@
     "picocolors": "^1.0.0",
     "postcss": "^8.4.19",
     "postcss-cli": "^10.0.0",
-    "purgecss": "^5.0.0",
     "stylelint": "^14.15.0",
     "stylelint-config-twbs-bootstrap": "^7.0.0",
     "svg-sprite": "^3.0.0-alpha1",