[eslint-plugin-react-compiler] Fix type error with recommended config

[niklasholm]

Summary

In the recommended configuration for eslint-plugin-react-compiler, i.e. reactCompiler.configs.recommended, the rule is typed as string rather than eslint.Linter.RuleEntry or anything assignable thereto, which results in the following type error if you type check your eslint configuration:

Property ''react-compiler/react-compiler'' is incompatible with index signature.
  Type 'string' is not assignable to type 'RuleEntry | undefined'.

Simply adding a const assertion fixes the error.

How did you test this change?

I emitted declarations for the module and confirmed that the rule is now typed as the string literal 'error'

[poteto]

Thanks!