chore(deps): update dependency @sourcegraph/eslint-config to ^0.20.4

Author: renovate-bot

package.json

@@ -40,7 +40,7 @@
   "devDependencies": {
     "@commitlint/cli": "^9.1.1",
     "@commitlint/config-conventional": "^9.1.1",
-    "@sourcegraph/eslint-config": "^0.17.2",
+    "@sourcegraph/eslint-config": "^0.20.4",
     "@sourcegraph/prettierrc": "^3.0.3",
     "@sourcegraph/tsconfig": "^4.0.1",
     "@types/chai": "4.2.12",