Migrate to ESLint 9 with flat config (#57110)

src/frame/lib/frontmatter.js

@@ -358,7 +358,6 @@ const semverRange = {
   format: 'semver',
   // This is JSON pointer syntax with ajv so we can specify the bad version
   // in the error message.
-  // eslint-disable-next-line no-template-curly-in-string
   errorMessage: 'Must be a valid SemVer range: ${0}',
 }