tools: remove no-useless-regex-char-class-escape

The `no-useless-regex-char-class-escape` custom lint rule was introduced as a less aggressive alternative to some enhancements that were introduced into ESLint. Those enhancements were blocking us from updating ESLint. However, they have since been relaxed and the custom rule is no longer needed. Remove it. Backport-PR-URL: #14360 PR-URL: #10561 Reviewed-By: Teddy Katz <[email protected]> Reviewed-By: James M Snell <[email protected]> Reviewed-By: Sam Roberts <[email protected]>

Author: Trott

.eslintrc.yaml

@@ -165,7 +165,6 @@ rules:
 # Custom rules in tools/eslint-rules
 align-multiline-assignment: 2
 assert-throws-arguments: [2,{requireTwo: true }]
-no-useless-regex-char-class-escape: [2,{override: ['[', ']'] }]
 
 # Global scoped method and vars
 globals: