ignore feature for @codecov/rollup-plugin

[Mister-Hope]

When using with tsdown, tsdown supports generating declaration files out of box(https://tsdown.dev/options/dts#config-file), so the codecov rollup plugin tracks declaration file size incorrectly.

See mdit-plugins/mdit-plugins#310 (comment) as an example.

I think @codecov/rollup-plugin shall provide a ignorePatterns same as bundle-analyzer CLI