Update devDependencies (twbs#34206)

* eslint                   ^7.27.0  →  ^7.28.0
* karma                     ^6.3.2  →   ^6.3.3
* karma-firefox-launcher    ^2.1.0  →   ^2.1.1
* rollup                   ^2.50.5  →  ^2.51.1

package.json

@@ -112,7 +112,7 @@
     "bundlewatch": "^0.3.2",
     "clean-css-cli": "^5.3.0",
     "cross-env": "^7.0.3",
-    "eslint": "^7.27.0",
+    "eslint": "^7.28.0",
     "eslint-config-xo": "^0.36.0",
     "eslint-plugin-import": "^2.23.4",
     "eslint-plugin-unicorn": "^31.0.0",
@@ -123,12 +123,12 @@
     "hugo-bin": "^0.71.1",
     "ip": "^1.1.5",
     "jquery": "^3.6.0",
-    "karma": "^6.3.2",
+    "karma": "^6.3.3",
     "karma-browserstack-launcher": "1.4.0",
     "karma-chrome-launcher": "^3.1.0",
     "karma-coverage-istanbul-reporter": "^3.0.3",
     "karma-detect-browsers": "^2.3.3",
-    "karma-firefox-launcher": "^2.1.0",
+    "karma-firefox-launcher": "^2.1.1",
     "karma-jasmine": "^4.0.1",
     "karma-jasmine-html-reporter": "^1.6.0",
     "karma-rollup-preprocessor": "^7.0.7",
@@ -138,10 +138,10 @@
     "npm-run-all": "^4.1.5",
     "postcss": "^8.3.0",
     "postcss-cli": "^8.3.1",
-    "rollup": "^2.50.5",
+    "rollup": "^2.51.1",
     "rollup-plugin-istanbul": "^3.0.0",
     "rtlcss": "^3.2.0",
-    "sass": "^1.32.13",
+    "sass": "1.32.13",
     "shelljs": "^0.8.4",
     "stylelint": "^13.13.1",
     "stylelint-config-twbs-bootstrap": "^2.2.0",