Support ESLint 10 when released

[MikeMcC399]

What would you like?

Support ESLint 10 in addition to ESLint 9

Why is this needed?

ESLint is planned for release in the next months. See blog What's coming in ESLint v10.0.0, Oct 3, 2025 which describes Alpha, Beta, release candidate and final releases during a period of November 2025 to January 2026.

Other

Expected tasks:

• Update the README documentation

• Update circle.yml to test both ESLint 9 and 10.

• Remove flat configuration option eslint-plugin-cypress/flat. This was replaced in eslint-plugin-cypress@5.0.0 by changing the default configuration eslint-plugin-cypress to be equivalent to eslint-plugin-cypress/flat, and at the same time eslint-plugin-cypress/flat was declared deprecated with a notice that it is planned to be removed in a future major version.