Remove the eslint-plugin-mozilla dependency

We only used two rules from the plugin which can both easily be replaced
nowadays:

- `mozilla/avoid-removeChild` is equal to the already active
  `unicorn/prefer-dom-node-remove` rule; please see [1] and [2].
- `mozilla/import-globals` is mostly obsolete nowadays ever since we
  removed the Firefox extension code from this repository and we
  eliminated most globals usage. The three remaining occurrences can be
  replaced with explicit `/* globals */` comments that we already use
  elsewhere, which overall is also more consistent.

[1] https://firefox-source-docs.mozilla.org/code-quality/lint/linters/eslint-plugin-mozilla/rules/avoid-removeChild.html
[2] https://github.com/sindresorhus/eslint-plugin-unicorn/blob/main/docs/rules/prefer-dom-node-remove.md

.eslintrc

@@ -7,7 +7,6 @@
   "plugins": [
     "import",
     "json",
-    "mozilla",
     "no-unsanitized",
     "sort-exports",
     "unicorn",
@@ -44,7 +43,6 @@
     "import/no-unresolved": ["error", {
       "ignore": ["display", "pdfjs", "pdfjs-lib", "pdfjs-web", "web", "fluent-bundle", "fluent-dom"],
     }],
-    "mozilla/avoid-removeChild": "error",
     "no-unsanitized/method": "error",
     "no-unsanitized/property": "error",
     "sort-exports/sort-exports": ["error", {

extensions/chromium/.eslintrc

@@ -7,16 +7,11 @@
     "webextensions": true
   },
 
-  "plugins": [
-    "mozilla"
-  ],
-
   "parserOptions": {
     "sourceType": "script"
   },
 
   "rules": {
-    "mozilla/import-globals": "error",
     "no-var": "off",
   },
 }

extensions/chromium/pdfHandler-vcros.js

@@ -14,7 +14,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 /* eslint strict: ["error", "function"] */
-/* import-globals-from pdfHandler.js */
+/* globals getViewerURL */
 
 (function () {
   "use strict";

extensions/chromium/pdfHandler.js

@@ -13,7 +13,7 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */
-/* import-globals-from preserve-referer.js */
+/* globals saveReferer */
 
 "use strict";
 

extensions/chromium/preserve-referer.js

@@ -13,7 +13,7 @@ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 See the License for the specific language governing permissions and
 limitations under the License.
 */
-/* import-globals-from pdfHandler.js */
+/* globals getHeaderFromHeaders */
 /* exported saveReferer */
 
 "use strict";