[lint] improve type safety on flat config

[davbrito]

Summary

This pull request refactors the way flat ESLint configs are defined and assigned in the eslint-plugin-react-hooks package. The main focus is on improving type safety and clarity by restructuring how the flat configuration is constructed and assigned.

The flat config was typed as Record<string, ReactHooksFlatConfig>, so it lacks editor auto-completions and could lead to spelling mistakes. This change preserves config names so it's easier and safer to use.

[react-sizebot]

Comparing: ead9218...571af48

Critical size changes

Includes critical production bundles, as well as any change greater than 2%:

Name	+/-	Base	Current	+/- gzip	Base gzip	Current gzip
oss-stable/react-dom/cjs/react-dom.production.js	=	6.68 kB	6.68 kB	+0.05%	1.83 kB	1.83 kB
oss-stable/react-dom/cjs/react-dom-client.production.js	=	604.98 kB	604.98 kB	=	107.14 kB	107.14 kB
oss-experimental/react-dom/cjs/react-dom.production.js	=	6.69 kB	6.69 kB	+0.11%	1.83 kB	1.83 kB
oss-experimental/react-dom/cjs/react-dom-client.production.js	=	663.95 kB	663.95 kB	=	117.03 kB	117.03 kB
facebook-www/ReactDOM-prod.classic.js	=	687.81 kB	687.81 kB	=	121.07 kB	121.07 kB
facebook-www/ReactDOM-prod.modern.js	=	678.24 kB	678.24 kB	=	119.42 kB	119.42 kB

Significant size changes

Includes any change greater than 0.2%:

(No significant changes)

Generated by 🚫 dangerJS against 571af48