fix(eslint-plugin): fix crash and false positives in `no-useless-default-assignment`#11845

JoshuaKGoldberg merged 10 commits intotypescript-eslint:maintypescript-eslint/typescript-eslint:mainfrom

ulrichstark:fix(eslint-plugin)--fix-crash-in-`no-useless-default-assignment`-if-no-signaturesulrichstark/typescript-eslint:fix(eslint-plugin)--fix-crash-in-`no-useless-default-assignment`-if-no-signaturesCopy head branch name to clipboard